FN ISI Export Format VR 1.0 PT J AU Hayman, B Wedel-Heinen, J Brondsted, P AF Hayman, Brian Wedel-Heinen, Jakob Brondsted, Pov TI Materials challenges in present and future wind energy SO MRS BULLETIN LA English DT Article ID FRP SANDWICH STRUCTURES; DELAMINATIONS; STRENGTH AB The main concept Currently in use in wind energy involves horizontal-axis wind turbines with blades of fiber composite materials. This turbine concept is expected to remain as the major provider of wind power in the foreseeable future. However, turbine sizes are increasing, and installation offshore means that wind turbines will be exposed to more demanding environmental conditions. Many challenges are posed by the use of fiber composites in increasingly large blades and increasingly hostile environments. Among these are achieving adequate stiffness to prevent excessive blade deflection, preventing buckling failure, ensuring adequate fatigue life under variable wind loading combined with gravitational loading, and minimizing the occurrence and consequences of production defects. A major challenge is to develop cost-effective ways to ensure that production defects do not cause unacceptable reductions in equipment strength and lifetime, given that inspection of large wind power structures is often problematic. C1 Univ Oslo, N-0316 Oslo, Norway. Det Norke Veritas, Danmark AS, Denmark. Tech Univ Denmark, Natl Lab Sustainable Energy, Riso DTU, Copenhagen, Denmark. CR *AM WIND EN ASS, 2001, COMP COST WIND OTH E *BTM CONS APS, 2007, INT WIND EN DEV WORL *DAN WIND IND ASS, WIND MAP W EUR *DELFT U TECHN, OPT DAT *DET NORSK RIS NAT, 2002, GUID DES WIND TURB *DNV OS, 2004, DNV0SJ101 *DNV OS, 2006, DNVOSJ102 *DOE MSU, DOE MSU COMP MAT FAT *ELS A S, 2000, HORNS REV OFFSH WIND *EUR UN, UPW PROJ *IEC, 2001, 6140023 IEC *IEC, 2005, 6140013 IEC *ITC WT, 2001, 01 IEC WT *US DEP EN EN EFF, WIND RES MAPS *US DEP EN REN RES, WIND EN RES ATL US *VEST WIND SYST, ENV IMP WIND TURB EN *VEST WIND SYST, 2006, LIF ASS OFFSH ONSH S *WALL WILH LOG, E S ORC ENV SOUND SH ARCHER CL, 2005, J GEOPHYS RES-ATMOS, V110, ARTN D12110 ASTRON BT, 1997, MANUFACTURING POLYM BERGGREEN C, 2004, THESIS TECHNICAL U D BERGGREEN C, 2005, J SANDW STRUCT MATER, V7, P483, DOI 10.1177/1099636205054790 BERGGREEN C, 2007, J COMPOS MATER, V41, P493, DOI 10.1177/0021998306065285 BERGGREEN CV, 2007, 1 INT C MAR STRUCT G, P413 BRONDSTED P, 2005, ANNU REV MATER RES, V35, P505, DOI 10.1146/annurev.matsci.35.100303.110641 BUDIANSKY B, 1983, COMPUT STRUCT, V16, P3 CRAWFORD RA, 2007, ENERGY SUSTAINABILIT, V105, P155 DESMET BJ, 1994, 3 IEA S WIND TURBINE EGGLESTON E, 2008, WAHT VERTICAL AXIS W HAYMAN B, 2005, THEORY APPL SANDWICH, P351 HAYMAN B, 2007, 1 INT C MAR STRUCT G, P435 HAYMAN B, 2007, J SANDW STRUCT MATER, V9, P377, DOI 10.1177/1099636207069250 HAYMAN B, 2007, J SANDW STRUCT MATER, V9, P571, DOI 10.1177/1099636207070853 HWANG SF, 2005, COMPOS STRUCT, V68, P157, DOI 10.1016/j.compstruct.2004.03.010 JANSSEN LGJ, 2006, ENCNC06023 JORGENSEN ER, 2004, RISOR1392EN RIS NAT KENSCHE CW, 1996, 16684 EUR, P38 LILHOLT H, 2006, P 27 RIS C MAT SCI P LIOYD G, 2004, GUIDELINE CERTIFICAT LUNDSGAARDLARSE.C, 2006, P 27 RIS C MAT SCI P, P375 MANDELL JF, 1997, SAND973002 SAND NAT MAYER RM, 1996, DESIGN COMPOSITE STR MISHNAEVSKY L, 2006, CYCLIC LOADING FREQU, V239 MISHNAEVSKY L, 2007, POLYMER COMPOSITE MA, V239 NIJSSEN R, 2006, THESIS DELT U DELFT SHORT GJ, 2002, COMPOS STRUCT, V58, P249 SKAMRIS C, 2002, TYPE APPROVAL SCHEME SORENSEN BF, 2005, R1526EN RIS NAT LAB SORENSEN BF, 2006, ENG FRACT MECH, V73, P2642, DOI 10.1016/j.engfracmech.2006.04.006 SORENSEN E, 2004, RISOR1390EN RISNAT L SOUTIS C, 1993, P ROY SOC LOND A MAT, V440, P241 VEDELD K, 2007, THESIS U OSLO OSLO WEDELHEINEN J, 2006, IMPLEMENTATION OPTIM WEDELHEINEN J, 2006, P 27 RIS C MAT SCI P, V115 NR 54 TC 0 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD APR PY 2008 VL 33 IS 4 BP 343 EP 353 PG 11 SC Materials Science, Multidisciplinary; Physics, Applied GA 279RT UT ISI:000254373000018 ER PT J AU Gao, J Chen, X Yilmaz, O Gindy, N AF Gao, Jian Chen, Xin Yilmaz, Oguzhan Gindy, Nabil TI An integrated adaptive repair solution for complex aerospace components through geometry reconstruction SO INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY LA English DT Article DE adaptive repair solution; aerospace components; defects; geometry reconstruction; blade machining ID TURBINE-BLADES; REVERSE; INSPECTION; SYSTEM; DESIGN AB The repair of worn parts is of great interest for aerospace industries to extend the life cycle of aerospace parts. Due to the distortion and defects of a worn part, the nominal CAD model from the design stage is no longer suitable for the use of the repairing process, which causes the main problem for precisely repairing complex components. In this paper, an integrated repair solution adaptive to worn component geometry is proposed and developed for aerospace industries. Based on the scanned repair model with different defects, a reverse engineering(RE)-based geometry reconstruction method is developed for the normal model creation of a worn component. This is a crucial procedure for precisely repairing individual component. Based on the nominal model reconstructed, tool paths used for the build-up and machining process can then be generated to implement the repairing work. In this study, repairing complex blades from aerospace engines were considered and practised. To verify the proposed repair solution, a curved blade to be repaired was used in the experiment and the blade tip model was reconstructed for the subsequent repairing process. Based on the model, the blade was built-up through a laser cladding process and then machined back to size through isoparametric machining strategy on a 5-axis Hermle machine tool. Finally, the experimental results are given and analysed. C1 Guangdong Univ Technol, Sch Mech & Elect Engn, Guangzhou 510090, Peoples R China. Univ Nottingham, Sch Mech Mat & Mfg Engn, Nottingham NG7 2RD, England. RP Gao, J, Guangdong Univ Technol, Sch Mech & Elect Engn, 729 E Dongfeng Rd, Guangzhou 510090, Peoples R China. EM gaojian@gdut.edu.cn CR 2001, LINE FIRE ENG JAN, P29 *INNOVMETRIC SOFTW, 2003, POL IMINSPECT COMP V *ROLLS ROYC PLC, 2002, COMPR BLAD REP OVE, P10 BARDELL R, 2003, J MATER PROCESS TECH, V133, P26 BREMER C, 2001, 3 INT C LAS ASS NET CHEN LC, 2000, ROBOT CIM-INT MANUF, V16, P161 DIX B, 2004, INT J AIRER ENG AERO, V76 GAO J, 2005, AIRCR ENG AEROSP TEC, V77, P34 GAO J, 2006, ADV ENG SOFTW, V37, P592, DOI 10.1016/j.advengsoft.2006.01.007 GAO J, 2006, INT J PROD RES, V44, P117, DOI 10.1080/09638280500219737 GAUMANN M, 2001, ACTA MATER, V49, P1051 HUANG H, J MAT PROCESS TECHNO, V127, P140 MOTAVALLI S, 1998, COMPUT IND ENG, V35, P25 RICHTER CH, 2003, COMPUT STRUCT, V81, P919, DOI 10.1016/S0045-7949(02)00426-1 SON S, 2002, INT J MACH TOOL MANU, V42, P889 STIMPER B, 2003, USING LASER POWDER C WALTON P, 2005, ADAPTIVE MACHINING S, P80 WERNER A, 1998, J MATER PROCESS TECH, V76, P128 ZHANG SJ, 2003, P I MECH ENG C-J MEC, V217, P81 NR 19 TC 0 PU SPRINGER LONDON LTD PI ARTINGTON PA ASHBOURNE HOUSE, THE GUILDWAY, OLD PORTSMOUTH ROAD, ARTINGTON GU3 1LP, GUILDFORD, ENGLAND SN 0268-3768 J9 INT J ADV MANUF TECHNOL JI Int. J. Adv. Manuf. Technol. PD APR PY 2008 VL 36 IS 11-12 BP 1170 EP 1179 PG 10 SC Automation & Control Systems; Engineering, Manufacturing GA 277ZK UT ISI:000254253000012 ER PT J AU Mucke, R Kiewel, H AF Muecke, Roland Kiewel, Holger TI Nonlocal cyclic life prediction for gas turbine components with sharply notched geometries SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID FATIGUE LIMIT; GROWTH; STRAIN AB The safe and efficient operation of modern heavy duty gas turbines requires a reliable prediction of fatigue behavior of turbine components. Fatigue damage is located in areas where cyclic stress and strain amplitudes are highest. Thus, geometrical notches associated with stress/strain concentrations and stress/strain gradients appear to be the most important sites for fatigue crack initiation. The paper addresses a nonlocal concept for cyclic life prediction of notched components. Contrary to various local approaches in the field, the proposed method explicitly accounts for stress and strain gradients associated with notches arising from grooves, cooling holes, fillets, and other design features with stress raising effect. As a result, empirical analytical expressions for considering either strain or stress gradients for cyclic life prediction are obtained. The method has been developed from cyclic test data on smooth and notched specimens made of a ferritic 1.5CrNiMo rotor steel. The analytical formulations obtained have then been applied to test data on the nickel base superalloy MAR-M247 CC showing a good agreement between prediction and measurement. Moreover, the proposed nonlocal lifing concept has been validated by component tests on turbine blade firtrees. The predicted number of cycles to failure correlates well with the experimental results showing the applicability of the proposed method to complex engineering designs. C1 Alstom, CH-5401 Baden, Switzerland. RP Mucke, R, Alstom, Brown Boveri Str 7, CH-5401 Baden, Switzerland. CR *KARLSS SOR INC, 2003, US MAN VERS 6 4, V3 BELLETT D, 2005, INT J FATIGUE, V27, P207, DOI 10.1016/j.ijfatigue.2004.07.006 CIAVARELLA M, 2004, INT J FATIGUE, V26, P289, DOI 10.1016/S0142-1123(03)00106-3 COFFIN LF, 1987, ENG FRACT MECH, V28, P485 DOWLING NE, 1999, MECH BEHAV MAT FILIPPINI M, 2000, INT J FATIGUE, V22, P397 GANGLOFF RP, 1981, FATIGUE ENG MATER, V4, P15 GLINKA G, 1987, INT J FATIGUE, V8, P235 HARKEGARD G, 2005, INT J FATIGUE, V27, P715, DOI 10.1016/j.ijfatigue.2004.10.004 JOHNSON HH, 1965, MATER RES STAND, V5, P442 MAKKONEN M, 2003, INT J FATIGUE, V25, P17 NAIK RA, 2005, INT J FATIGUE, V27, P481, DOI 10.1016/j.ijfatigue.2004.10.003 NODA NA, 2006, INT J FATIGUE, V28, P151, DOI 10.1016/j.ijfatigue.2005.04.015 PETERSON RE, 1974, STRESS CONCENTRATION QYLAFKU G, 1999, INT J FATIGUE, V21, P753 SEHITOGLU H, 1983, ENG FRACT MECH, V18, P609 SIEBEL E, 1955, VDI Z, V97, P121 STEINCHEN W, 1998, J STRAIN ANAL ENG, V33, P171 STEINCHEN W, 1999, MEASUREMENT, V26, P79 SURESH S, 1991, FATIGUE MAT TAYLOR D, 1994, ENG FAIL ANAL, V1, P275 XU RX, 1995, FATIGUE FRACT ENG M, V18, P885 NR 22 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2008 VL 130 IS 1 DI DOI 10.1115/1.27476421 PG 8 SC Engineering, Mechanical GA 267BU UT ISI:000253484200030 ER PT J AU Rahmani, K Nategh, S AF Rahmani, Kh. Nategh, S. TI Influence of aluminide diffusion coating on the tensile properties of the Ni-base superalloy Rene 80 SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE Ni-base superalloy; Rene 80; aluminide coating; tensile properties; fracture strain; DBTT ID LOW-CYCLE FATIGUE; TURBINE-BLADES; TEMPERATURE; BEHAVIOR; LCF AB Ni-base superalloy Rene 80 is widely used in manufacturing aircraft turbine blades. The service temperature of this alloy is in the range of 760-982 degrees C. Although this alloy possesses suitable mechanical, oxidation and hot corrosion properties, it is coated in order to increase its wear, oxidation, erosion and hot corrosion properties against harmful environmental service conditions. In this paper the influence of applying diffusion coating (CODEP-B) on the tensile properties of Rene 80 has been studied in the temperature range of 22-982 degrees C. Experimental results show that the tensile properties of the coated specimens are relatively lower than that of uncoated ones in the same conditions. But in the service conditions, coating could have some useful and positive effects practically. In aircraft turbines in service conditions, the maximum strain the blades experience is always bellow 1% and in this range of strain no crack initiates and generates on the applied coating surface. Thus in this situation, the coating would certainly have protective properties preventing from oxidation, hot corrosion and erosion of the base metal. Published by Elsevier B.V. C1 Power & Water Ind Univ, Fac Energy Engn, Tehran, Iran. Sharif Univ Technol, Fac Mat Sci & Engn, Tehran, Iran. RP Rahmani, K, Power & Water Ind Univ, Fac Energy Engn, Tehran Pars Ave, Tehran, Iran. EM khrahmani1970@yahoo.com CR *INT ASM, 2000, ASM HDB ANTOLOVICH SD, 1981, METALL TRANS A, V12, P473 ANTOLOVITCH SD, 1979, MET T A, V10, P1859 BHATTACHAR VS, 1993, J ENG MATER-T ASME, V115, P351 CHANG WH, 1972, TENSILE EMBITTERMENT, P636 DOMAS PA, 1985, ENG FRACT MECH, V21, P203 DONACHIE MJ, 2002, SUPERALLOYS TECHNICA ESKNER M, MECH BEHAV TURBINE C ESKNER M, 2003, SURF COAT TECH, V165, P21 GOSWAMI T, 2001, MATER DESIGN, V22, P217 GOWARD GW, 1970, J MET, V22, P31 GRUNLING HW, 1987, MATER SCI ENG, V88, P177 KAMEDA J, 1997, MAT SCI ENG A-STRUCT, V229, P42 KOLKMAN HJ, 1987, MATER SCI ENG, V89, P81 NAEEM M, 1999, INT J FATIGUE, V21, P831 SAFARI J, 2005, THESIS SHARIF U SHEN P, 1986, MATER SCI ENG, V78, P163 SHEN P, 1986, MATER SCI ENG, V78, P171 VOGEL D, 1987, MATER SCI ENG, V88, P227 WEBB G, 1996, SUPERALLOYS, P345 WOLLNER S, 2003, SURF COAT TECH, V167, P83, DOI 10.1016/S0257-8972(02)00843-5 ZHANG YH, 1997, SCRIPTA MATER, V37, P815 NR 22 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JAN 15 PY 2008 VL 202 IS 8 BP 1385 EP 1391 PG 7 SC Materials Science, Coatings & Films; Physics, Applied GA 254QD UT ISI:000252601500007 ER PT J AU Desale, GR Gandhi, BK Jain, SC AF Desale, Girish R. Gandhi, Bhupendra K. Jain, S. C. TI Slurry erosion of ductile materials under normal impact condition SO WEAR LA English DT Article DE ductile material; normal impact condition; hardness ratio; pot tester; slurry erosion ID POT TESTER; PARTICLE-SIZE; WEAR; METALS; STEEL; VELOCITY; DESIGN; SHAPE; FLOW; ORIENTATION AB The phenomenon of erosion wear at normal impact of solid-liquid mixture has been studied in a slurry pot tester. The erosion wear tests have been carried out using seven different ductile type materials namely aluminium alloy (AA6063), copper, brass, mild steel, AISI 304L stainless steel, AISI 316L stainless steel, and turbine blade steel using three erodents namely, quartz, alumina and silicon carbide. Experiments are performed at 3 m/s velocity and 10 wt% concentration of 550 mu m size particles for combination of different erodent and target materials at normal impact condition. It is observed that the wear at normal impact condition is a strong function of hardness ratio of erodent and target materials. Experiments are also carried out for different solid concentrations, particle sizes and velocities. Based on the experimental data, a correlation is proposed to predict the erosion wear at normal impact condition. (c) 2007 Elsevier B.V. All rights reserved. C1 Indian Inst Technol, Dept Mech & Ind Engn, Roorkee 247667, Uttar Pradesh, India. RP Gandhi, BK, Indian Inst Technol, Dept Mech & Ind Engn, Roorkee 247667, Uttar Pradesh, India. EM bkgmefme@iitr.ernet.in CR ABBADE NP, 2000, TRIBOL INT, V33, P811 BAHADUR S, 1990, WEAR, V138, P189 BITTER JGA, 1962, WEAR, V6, P5 BITTER JGA, 1963, WEAR, V6, P169 BOUWMAN AM, 2004, POWDER TECHNOL, V146, P66, DOI 10.1016/j.powtec.2004.04.044 CLARK HM, 1992, WEAR, V152, P223 CLARK HM, 1995, WEAR, V186, P454 DEBREE SEM, 1982, EROSION RESISTANCE W, V8 DESALE GR, 2004, P 31 NAT C FLUID MEC, P890 DESALE GR, 2005, WEAR 1, V259, P196, DOI 10.1016/j.wear.2005.02.068 ELKHOLY A, 1983, WEAR, V84, P39 FENG Z, 1999, WEAR, V233, P674 FINNIE I, 1960, WEAR, V3, P87 FOLEY T, 1983, WEAR, V91, P45 GANDHI BK, 1999, TRIBOL INT, V32, P275 GANDHI BK, 2001, JSME INT J B-FLUID T, V44, P231 GANDHI BK, 2003, WEAR, V254, P1233, DOI 10.1016/S0043-1648(03)00109-1 GUPTA R, 1995, WEAR, V184, P169 HUMPHREY JAC, 1990, INT J HEAT FLUID FL, V11, P170 HUTCHINGS IM, 1979, EROSION PREVENTION U, P59 HUTCHINGS IM, 1981, WEAR, V70, P269 LEVY AV, 1981, WEAR, V68, P269 LEVY AV, 1983, WEAR, V89, P151 LEVY AV, 1984, WEAR, V98, P163 LEVY AV, 1985, WEAR, V101, P117 LI SK, 1981, WEAR, V73, P295 LIEBHARD M, 1991, WEAR, V151, P381 LIN FY, 1991, WEAR, V141, P279 LIN FY, 1991, WEAR, V143, P231 STACHOWIAK GW, 1987, NATL C PUBLICATION, V8718, P255 STACK MM, 1999, MATER SCI TECH SER, V15, P337 SUNDARARAJAN G, 1983, WEAR, V84, P237 TSAI W, 1981, WEAR, V68, P289 ZITOUN KB, 2001, INT J MULTIPHAS FLOW, V27, P1397 ZU JB, 1990, WEAR, V140, P331 NR 35 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD FEB 4 PY 2008 VL 264 IS 3-4 BP 322 EP 330 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 251KO UT ISI:000252372300020 ER PT J AU Morris, A Kourmpetis, M Dear, ID Sjodahl, M Dear, JP AF Morris, A. Kourmpetis, M. Dear, I. D. Sjodahl, M. Dear, J. P. TI Optical strain monitoring techniques for life assessment of components in power generation plants SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Article DE high-temperature strain measurement; auto-reference creep management and control system; digital image correlation; remaining service life ID ELECTRONIC SPECKLE PHOTOGRAPHY; ACCURACY AB The current paper presents the ongoing development of a combination of two methods for monitoring creep strain in mechanical components of electrical power generation plants. This is to obtain, during plant shut-down maintenance periods, needed data to assess the remaining life of installed steam pipes and other components. Related to this research, but not reported on in the current paper, is the development of monitoring for detection of the onset of fatigue and other failure processes in wind turbine generator blades. The auto-reference creep management and control (ARCMAC) system uses precision optics and a charge-coupled device (CCD) camera for uniaxial and biaxial strain measurement. Digital image correlation (DIC) is employed to obtain strain distribution data about the ARCMAC point-to-point monitored sites. These and other systems are being developed to obtain a more comprehensive range of life assessment data. This is mostly for assessing longevity of steam pipes and other components in power stations that are subject to demanding and hostile operational environments. These permanently installed monitoring systems need to be rugged to withstand the demanding heat and mechanical forces to which they are subjected and of a compact design so they can be sited in difficult-to-access locations. This is one of the advantages of the combined ARCMAC and DIC system that is further being developed. These systems are essential for cost-effective management of power plant operation and maintenance and for achieving reliable continuity of service. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mech Engn, London SW7 2AZ, England. Power Technol Inc, EON UK, Nottingham, England. Brunel Univ, Sch Engn & Design, Uxbridge UB8 3PH, Middx, England. Lulea Univ Technol, Div Expt Mech, S-95187 Lulea, Sweden. RP Dear, JP, Univ London Imperial Coll Sci Technol & Med, Dept Mech Engn, S Kensington Campus, London SW7 2AZ, England. EM j.dear@imperial.ac.uk CR *API, 2000, 579 API *GOM, DEF MEAS SYST *LAVISION, DEF MEAS SYST *NAT I STAND, 2004, MEAS SOFTW BURGUETE R, 2006, BSSM WORKSH DIG IM C, P5 CANE BJ, 1982, INT J PRES VES PIP, V10, P11 HILD F, 2006, STRAIN, V42, P69 MORRIS A, 2006, STRAIN, V42, P181 MORRIS AP, 2006, ASME PVP 2006 ICPVT, P93065 MORRIS AP, 2006, ASME PVP 2006 ICPVT, P93066 PATTERSON E, 2006, INT C FULL FIELD MEA, P3 PRAGER M, 1995, J PRESS VESS-T ASME, V117, P95 PURI A, 2006, DIC ARCMAC STRAIN ME SINGLETON K, 2005, CREEP MONITORING HIG SJODAHL M, 1994, APPL OPTICS, V33, P6667 SJODAHL M, 1997, APPL OPTICS, V36, P2875 TURSKI M, 2006, BSSM WORKSH DIG IM C, P9 NR 17 TC 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 0957-6509 J9 PROC INST MECH ENG A-J POWER JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PD DEC PY 2007 VL 221 IS A8 BP 1141 EP 1152 PG 12 SC Engineering, Mechanical GA 253ME UT ISI:000252521500007 ER PT J AU Romanov, EP Petrova, SN Vinogradova, NI Kochetkova, TN Stepanova, NN Vinokurov, GG Yakovleva, SP AF Romanov, E. P. Petrova, S. N. Vinogradova, N. I. Kochetkova, T. N. Stepanova, N. N. Vinokurov, G. G. Yakovleva, S. P. TI Effect of prolonged high-temperature loading on the structure of the KhN65VMTYu alloy SO PHYSICS OF METALS AND METALLOGRAPHY LA English DT Article AB A complex analysis of changes in the structure and in the phase composition arising as a result of both a prolonged operation of articles made of the alloy KhN65VMTYu (EI893) and after conducting imitation tests of model samples. The tests for long-term strength using samples cut out from the body of a large-dimension turbine blade which was exploited for 63 622 h showed that the blade preserved a significant residual reserve of service life (at 750 degrees C and 250 MPa, the time to failure is 4243.5 h). C1 Russian Acad Sci, Inst Met Phys, Ural Div, Ekaterinburg 620041, Russia. Inst Physicotech Problems N, Yakutsk 677980, Russia. RP Romanov, EP, Russian Acad Sci, Inst Met Phys, Ural Div, Ul S Kovalevskoi 18, Ekaterinburg 620041, Russia. CR BORZDKA AM, 1990, METALLOV TERM OBRAB, P2 KANAIKIN VA, 2000, DAMAGE FRACTURE BLAD MASLENKOV SB, 1983, HIGH TEMPERATURE STE ROMANOV EP, 2004, P 2 EUR S PROBL STRE, P285 RTISHCHEV VV, 1986, OPTIMIZATION PROCESS, P8 NR 5 TC 0 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0031-918X J9 PHYS METALS METALLOGR ENGL TR JI Phys. Metals Metallogr. PD NOV PY 2007 VL 104 IS 5 BP 535 EP 539 PG 5 SC Metallurgy & Metallurgical Engineering GA 249TZ UT ISI:000252254000013 ER PT J AU Nutzel, R Affeldt, E Goken, M AF Nuetzel, R. Affeldt, E. Goeken, M. TI Damage evolution during thermo-mechanical fatigue of a coated monocrystalline nickel-base superalloy SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE oxidation resistant coating; thermo-mechanical fatigue; nickel-base superalloys; crack initiation; platinum alummide AB To prevent hot gas corrosion nickel-base turbine blades used in today's jet engines, they are protected with so called Pt-modified beta-NiAl coatings which are also subjected to thermo-mechanical loading during service. The effects of thermo-mechanical fatigue (TMF) loading on the coating as well as TMF life are the subjects of this paper. Microstructural investigations before, during and after thermo-mechanical fatigue treatment using atomic force and scanning electron microscopy on the monocrystalline nickel-base alloy PWA1484 were conducted to reveal the dominating failure mechanisms. (C) 2007 Elsevier Ltd. All rights reserved. C1 Univ Erlangen Nurnberg, Dept Mat Sci & Engn, Inst Gen Mat Properties WW 1, D-91058 Erlangen, Germany. MTU Aero Engines, D-80995 Munich, Germany. RP Nutzel, R, Univ Erlangen Nurnberg, Dept Mat Sci & Engn, Inst Gen Mat Properties WW 1, Martens Str 5, D-91058 Erlangen, Germany. EM ralf.nuetzel@ww.uni-erlangen.de CR AFFELDT EE, 2000, ADV ENG MATER, V2, P811 ANTELO MA, 1998, MAT SCI ENG A-STRUCT, V247, P40 BAUER R, 1985, HIGH TEMP TECHNOL, V3, P59 DURST K, 2004, METALLOGRAPHIE TAGUN, P117 DURST K, 2004, SUPERALLOYS 2004, P467 GRUBE F, 2002, ASTM STP, V1428 GRUBE F, 2003, THESIS U ERLANGEN NU GRUBE F, 2004, P 5 INT C LOW CYCL F, P309 MEVREL R, 1986, MATER SCI TECH SER, V2, P201 MIRACLE DB, 1993, ACTA METALL MATER, V41, P649 NR 10 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD FEB PY 2008 VL 30 IS 2 BP 313 EP 317 PG 5 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 245IG UT ISI:000251927700015 ER PT J AU Scholz, A Schmidt, A Walther, HC Schein, M Schwienheer, M AF Scholz, Afred Schmidt, Andreas Walther, Hans Christian Schein, Mathias Schwienheer, Michael TI Experiences in the determination of TMF, LCF and creep life of CMSX-4 in four-point bending experiments SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE CMSX-4; creep; LCF; TMF; four-point bending test AB The thermo-mechanical fatigue (TMF), low cycle fatigue (LCF) and creep life of rectangular flat specimen were evaluated by means of four-point bending tests. Experiments were performed on the single crystal superalloy CMSX-4 mainly in the orientation (00 1), but also orientations (0 1 1) and (1 1 1). While the TMF-Tests were performed in the temperature ranges from 250 to 750 degrees C, 450-950 degrees C and 550-1050 degrees C with a heating rate of 25 degrees C/s and a cooling rate of 12.5 degrees C/s, the LCF and creep tests were performed at 750, 950 and 1050 degrees C. Two different bending devices were designed and machined for the creep test and the LCF and TMF test respectively. In this work the experiences with the design and performance of the experimental test setup of the LCF and TMF experiments, especially with temperature and strain control are reported. Results and theoretical interpretation are given in [Xu J, Reuter S, Rothkegel W. Tensile and bending thermo-mechanical fatigue testing on cylindrical and flat specimens of CMSX-4 for design of future high-pressure turbine blades, TMF-Workshop, 22-23 September, Berlin; 2005.]. (C) 2007 Elsevier Ltd. All rights reserved. C1 Tech Univ Darmstadt, Inst Mat Technol, D-64283 Darmstadt, Germany. RP Scholz, A, Tech Univ Darmstadt, Inst Mat Technol, Grafen Str 2, D-64283 Darmstadt, Germany. EM scholz@ifw.tu-darmstadt.de CR EGLY T, 2005, TMF WORKSH 22 23 SEP HAHNER P, 2006, GRD2200030014 KUHN HJ, 2002, TMF VERSUCH EINFLUSS, P266 MEERSMANN J, 1994, MAT ADV POWER ENG 1, P841 REMY L, 2002, P FATIGUE, P1045 SCHOLZ A, 2000, EXPERIENCE SERVICE T SCHOLZ A, 2003, P LCF, V5 SCHOLZ A, 2004, ACTA METALLURGICA, V17 XU J, 2005, TMF WORKSH 22 23 SEP YAMAZAKI Y, 2006, SURF COAT TECH, V201, P744, DOI 10.1016/j.surfcoat.2005.12.023 NR 10 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD FEB PY 2008 VL 30 IS 2 BP 357 EP 362 PG 6 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 245IG UT ISI:000251927700022 ER PT J AU Xu, J Reuter, S Rothkegel, W AF Xu, J. Reuter, S. Rothkegel, W. TI Tensile and bending thermo-mechanical fatigue testing on cylindrical and flat specimens of CMSX-4 for design of turbine blades SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE CMSX-4; TMF test; bending test; fatigue modelling; life prediction AB This paper briefly describes thermo-mechanical fatigue tests performed on cylindrical and flat specimens of the single crystal material CMSX-4 in (0 0 1), (0 1 1) and (1 1 1)-orientation. The test matrix was defined based on the thermo-mechanical loading identified at different positions of actual turbine rotor blades. It included tensile strain-controlled TMF-test conditions on the cylindrical plain specimens and tensile load-controlled TMF-test conditions on the flat specimens with a variable number of straight and angled holes. Flat specimens without holes were tested under load-controlled bending TMF conditions. Different cycle types of in-phase, out-of-phase and phase-shift were applied. A summary is given about the test results including S-N-curves, fracture sections and hysteresis loops and about empirical modeling for prediction of fatigue life of the material. The developed algorithms that predicted the lives in good agreement with the experimental ones cover a large range of thermo-mechanical loading conditions and are applicable to the design of future turbine blades. (C) 2007 Elsevier Ltd. All rights reserved. C1 Rolls Royce Deutschland Ltd & Co KG, D-15827 Blankenfelde Mahlow, Germany. RP Xu, J, Rolls Royce Deutschland Ltd & Co KG, Eschenweg 11, D-15827 Blankenfelde Mahlow, Germany. EM jianmin.xu@rolls-royce.com CR BELENLIOGLU E, 2001, BERECHNUNG ORTHOTROP EGLY L, HIGH TEMP TMF C BERL LEVKOVITCH V, 2000, UNTERSUCHUNG VEREINH LEVKOVITCH V, 2005, THESIS U DORTMUND MACLACHLAN DW, 1997, CREEP FRACTURE ENG M, P707 MACLACHLAN DW, 2001, MAT SCI ENG A-STRUCT, V302, P275 SCHOLZ S, HIGH TEMP TMF C BERL TCHANKOV D, 2003, LOW CYCLE FATIGUE CR TCHANKOV DS, 2003, 5 INT C LOW CYCL FAT NR 9 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD FEB PY 2008 VL 30 IS 2 BP 363 EP 371 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 245IG UT ISI:000251927700023 ER PT J AU Oka, YI Yoshida, T Yamada, Y Yasui, T Hata, S AF Oka, Y. I. Yoshida, T. Yamada, Y. Yasui, T. Hata, S. TI Evaluation of erosion and fatigue resistance of ion plated chromium nitride applied to turbine blades SO WEAR LA English DT Article DE dynamic hardness; erosion by solid particle impact; fatigue strength; ion plated material; martensitic stainless steel; high temperature environment ID SOLID PARTICLE IMPACT; MECHANICAL-PROPERTIES; PRACTICAL ESTIMATION; DAMAGE; COATINGS AB High temperature oxidation and erosion resistant ceramic coating materials have been recently used for turbine rotor blades under high temperature dry steam conditions. It is, therefore, important to evaluate not only the physical or mechanical properties but also characteristics of erosion and fatigue of such materials for purposes of material selection and to predict the working life of plants. Ion plated CrN samples with a sublayer of plasma nitride on martensitic stainless steel were prepared. Dynamic hardness, in a high temperature environment of 723 K, was obtained by the impact of a glass ball. Fatigue tests of the CrN coating materials were conducted at 723 K, the same temperature as is typically used in the environment of turbine rotor blades, and the results were compared with fatigue resistance at room temperature. Erosion tests by the impact of SiO2 particles with a mean diameter of 326 mu m at an impact velocity of 104 m s(-1) were performed at room temperature to evaluate the fundamental erosion resistance, and the dependence of impact angle on erosion damage of CrN coating materials was compared with the resistance of an alumina bulk material. Consequently, the erosion rates at room temperature and the dynamic hardness distributions of the CrN coating materials at 723 K indicated that the materials used in this study had excellent erosion resistance and the fatigue tests for the coating materials indicated the possibility of applications to actual turbine blades that are used at 723 K. (C) 2007 Elsevier B.V. All rights reserved. C1 Hiroshima Univ, Dept Chem Engn, Higashihiroshima 7398527, Japan. Mitsubishi Heavy Ind Co Ltd, Hirst Res & Dev Ctr, Nishi Ku, Hiroshima 7330036, Japan. Mitsubishi Heavy Ind Co Ltd, Hiroshima Machinery Works, Nishi Ku, Hiroshima 7330036, Japan. RP Oka, YI, Hiroshima Univ, Dept Chem Engn, 1-4-1 Kagmiyama, Higashihiroshima 7398527, Japan. EM iyoshi@hiroshima-u.ac.jp CR BARBER J, 2005, WEAR 1, V259, P125, DOI 10.1016/j.wear.2005.02.008 BOSE K, 2005, WEAR 1, V259, P135, DOI 10.1016/j.wear.2005.02.043 GAO S, 2003, ENG FRACT MECH, V70, P1573, DOI 10.1016/S0013-7944(02)00123-6 OKA YI, 2001, WEAR 1, V250, P736 OKA YI, 2005, WEAR 1, V259, P102, DOI 10.1016/j.wear.2005.01.040 OKA YI, 2005, WEAR 1, V259, P95, DOI 10.1016/j.wear.2005.01.039 OKA YI, 2005, WEAR, V258, P92, DOI 10.1016/j.wear.2004.04.012 OKA YI, 2006, MATER SCI FORUM, V522, P417 SARGENT GA, 1979, ASTM STP, V664, P77 WEN M, 2005, MAT SCI ENG A-STRUCT, V398, P99, DOI 10.1016/j.msea.2005.03.020 NR 10 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD SEP 10 PY 2007 VL 263 PN Part 1 Sp. Iss. SI BP 379 EP 385 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 217LY UT ISI:000249950600047 ER PT J AU Hager, CH Sanders, J Sharma, S Voevodin, A AF Hager, C. H., Jr. Sanders, J. Sharma, S. Voevodin, A. TI Gross slip fretting wear of CrCN, TiAlN, Ni, and CuNiIn coatings on Ti6Al4V interfaces SO WEAR LA English DT Article DE fretting wear; Ti6Al4V; gross slip; coatings; CrCN; TiAlN ID SLIDING METALS; TITANIUM; ALLOYS; TEMPERATURE; MECHANISM; FRICTION; BEHAVIOR AB Fretting is a low amplitude oscillatory wear that occurs at component interfaces and can accelerate crack initiation as well as interfacial degradation. Prevalent in Ti-alloy contacts, fretting wear often occurs at the blade/disk interfaces of fan and compressor stages in turbine engines, causing premature component failure. In many cases, plasma sprayed CuNiIn (copper-nickel-indium) coatings and solid lubricants are applied to blade roots to mitigate the fretting problem. However, the CuNiIn coatings can cause severe damage to the uncoated Ti-alloy counter parts once the solid lubricants wear out. In this study, bench level gross slip fretting wear tests were conducted at room temperature on unlubricated Ti6A14V (titanium, 6% aluminum, 4% vanadium) surfaces mated with CuNiln and commercially pure Ni plasma sprayed surfaces. Upon analysis, it was determined that the uncoated Ti6A14V surfaces initially gall. Then the resulting adherent wear particles break up causing a transition into a third body type wear mode over time. This leads to an accumulation of wear that is similar to that of uncoated Ti6A14V mating surfaces. Additional tests were conducted after applying 2-mu m thick PVD deposited TiAlN (titanium-aluminium-nitride) and CrCN (chrome-carbon-nitride) coatings to the surfaces of a second set of Ti6A14V mating pairs. When worn against the unlubricated CuNiln and Ni coatings, the thin TiAlN and CrCN coatings wore gradually without delaminating or cracking and were able to mitigate galling and extend test life. The application of the hard coatings lead to a reduction in wear in all of the tests except with the combination of TiAlN worn against CuNiln. Published by Elsevier B.V. C1 United Technol Corp, Dayton, OH 45432 USA. MLBT, AFRL, Wright Patterson AFB, OH 45433 USA. RP Hager, CH, United Technol Corp, 1270 N fairrffield Rd, Dayton, OH 45432 USA. EM carl.hager@wpafb.af.mil CR BLANCHARD P, 1991, METALL TRANS A, V22, P1535 BLAU PJ, 1981, WEAR, V72, P55 BOWDEN FP, 1943, J APPL PHYS, V14, P80 FAYEULLE S, 1993, TRIBOL T, V36, P267 FREIMANIS AJ, 2000, TRIBOL T, V43, P653 HAGER CH, 2004, WEAR, V257, P167, DOI 10.1016/j.wear.2003.10.023 HURRICKS PL, 1970, WEAR, V15, P389 PRIVETT H, 1994, METALL TECHNOL PRACT, P401 RIGNEY DA, 1979, WEAR, V53, P345 SAUGER E, 2000, WEAR, V245, P39 STOTT FH, 1973, CORROS SCI, V13, P449 TOMASHOV N, 1966, THEORY CORROSION PRO WATERHOUSE RB, 1992, INT MATER REV, V37, P77 ZHOU ZR, 1995, WEAR, V181, P531 NR 14 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD SEP 10 PY 2007 VL 263 PN Part 1 Sp. Iss. SI BP 430 EP 443 PG 14 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 217LY UT ISI:000249950600053 ER PT J AU Remy, L Alam, A Haddar, N Koster, A Marchal, N AF Remy, Luc Alam, Adil Haddar, Nader Koester, Alain Marchal, Nicolas TI Growth of small cracks and prediction of lifetime in high-temperature alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE fatigue crack growth; short cracks; creep-oxidation-fatigue interaction; damage model; life prediction; superalloys; stainless steel ID LOW-CYCLE FATIGUE; HOLD TIME; PROPAGATION; MODEL; INITIATION; OXIDATION; STRENGTH; BEHAVIOR; DEFECTS; CLOSURE AB The lifetime to initiate an engineering crack is usually predicted from S-N curves in high cycle fatigue or Coffin-Manson curves in low-cycle fatigue. This paper investigates how to predict the engineering life to initiate an engineering crack from the growth of small cracks. Small cracks can nucleate from defects and especially ceramic inclusions in superalloys produced by powder metallurgy. The behavior of short cracks nucleated from artificial defects was investigated under small scale yielding. A deterministic prediction of the life of smooth specimens was made using the growth law measured in air or in vacuum. The distribution of real defects was then used in a probabilistic life prediction model. The growth of small cracks under large scale yielding was investigated in stainless steels. A modified Tomkins equation can account for the behavior of small cracks and provide an estimate of the lifetime under low-cycle fatigue or thermal fatigue. A damage model based on the propagation of micro-cracks originating at casting defects has been developed for single crystal turbine blades, operating under thermo-mechanical creep-fatigue conditions. The model used the process zone concept introduced by Mc Clintock. Weakening of material due to localized oxidation embrittlement is shown to account for oxidation-creep-fatigue interactions. The model gives satisfactory life predictions under various thermo-mechanical loading conditions. A local approach to fracture is proposed for fatigue crack growth using a fracture criterion as a post-processor of a finite element model, for two-dimensional long cracks. (c) 2007 Published by Elsevier B.V. C1 ParisTech, CNRS, Ctr Mat Mines Paris, UMR 7633, F-91003 Evry, France. RP Remy, L, ParisTech, CNRS, Ctr Mat Mines Paris, UMR 7633, BP 87, F-91003 Evry, France. EM luc.remy@mat.ensmp.fr CR ALAM AM, 2005, P 11 INT C FRACT MAR BEEVERS CJ, 1984, ENG FRACT MECH, V19, P93 BOETTNER RC, 1965, T METALL SOC AIME, V233, P379 BOUBIDI P, 2002, HIGH TEMPERATURE FAT, P167 BRUCKNERFOIT A, 1993, FATIGUE FRACT ENG M, V16, P891 CHABOCHE JL, 1982, ASTM STP, V770, P81 CHALANT G, 1980, ACTA METALL, V28, P75 CHATEAU E, 2001, P 7 EUR C JUN 10 14 COFFIN LF, 1973, ASTM STP, V520, P5 DEBUSSAC A, 1994, FATIGUE FRACT ENG M, V17, P1319 DOWLING NE, 1976, ASTM STP, V590, P82 FRANKLIN CJ, 1978, HIGH TEMPERATURE ALL, P513 GOLDMAN NL, 1975, INT J SOLIDS STRUCT, V11, P575 GRISON J, 1994, FATIGUE CRACK INITIA GRISON J, 1997, ENG FRACT MECH, V57, P41 HADDAR N, 2002, P 8 INT FAT C, V3, P1665 HADDAR N, 2003, THESIS ECOLE MINES P HYZAK JM, 1982, METALL T A, V13, P33 KOSTER A, 2002, ESIS PUBLICATION, V29, P203 LAUTRIDOU JC, 1990, HIGH TEMPERATURE MAT, P1163 LAUTRIDOU JC, 1993, FATIGUE 93, V1, P285 MANSON SS, 1973, ASTM STP, V520, P744 MARCHAL N, 2006, COMP MATER SCI, V7, P42 MARCHAL N, 2006, P 9 EUR MECH MAT C L, P353 MARCHAL N, 2006, P 9 INT FAT C MAY 14, P10 MCCLINTOCK FA, 1963, FRACTURE SOLIDS, P65 MCEVILY AJ, 1963, ACTA METALL, V11, P725 MERIC L, 1991, J ENG MATER-T ASME, V113, P162 MINAKAWA K, 1983, FATIGUE ENG MATER, V6, P359 MURAKAMI Y, 1988, ASTM STP, V942, P1048 MURAKAMI Y, 1994, INT J FATIGUE, V16, P163 OHTANI R, 1994, HDB FATIGUE CRACK PR, P1347 OKAZAKI M, 1983, METALL TRANS A, V14, P1641 OSTERGREN WJ, 1976, J TEST EVAL, V4, P327 PINEAU A, 1981, ADV FRACTURE RES, V2, P553 PROBSTHEIN M, 2001, PREDICTIVE MICROSTRU RABOTNOV YN, 1969, CREEP PROBLEMS STRUC REMY L, 1992, ESIS, V12, P283 REMY L, 1993, ASTM STP, V1186, P3 REMY L, 2003, COMPREHENSIVE STRUCT, V5, P113 REMY L, 2003, COMPREHENSIVE STRUCT, V5, P113 REZAIARIA F, 1989, ENG FRACT MECH, V34, P283 SCHMITT W, 2002, FATIGUE 2002, V2, P781 SHIH CF, 1976, J ENG MAT TECHNOLOGY, V98, P289 SKELTON RP, 1988, ASTM STP, V942, P209 SONIAK F, 1986, EGF PUB, V1, P133 SONIAK F, 1990, FATIGUE, V3, P1583 SPERA DA, 1969, D5317 NASATM TAIRA S, 1973, ASTM STP, V520, P80 TAIRA S, 1979, T ASME, V101, P162 TERANISHI H, 1979, METALL T A, V10, P1806 TOMKINS B, 1968, PHILOS MAG, V18, P1041 WAREING J, 1977, MET SCI, V11, P439 NR 53 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 15 PY 2007 VL 468 SI Sp. Iss. SI BP 40 EP 50 PG 11 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 222EJ UT ISI:000250278600007 ER PT J AU Lau, YL Leung, RCK So, RMC AF Lau, Y. L. Leung, R. C. K. So, R. M. C. TI Vortex-induced vibration effect on fatigue life estimate of turbine blades SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID NUMERICAL-SIMULATION; TRANSONIC COMPRESSOR; TRAILING-EDGE; FLOW; WAKE; PREDICTION; NOISE; RESONANCE; VORTICES; AIRFOILS AB An analysis of a turbine blade fatigue life that includes the physics of fluid-structure interaction on the high cycle fatigue (HCF) life estimate of turbine blades is carried out. The rotor wake excitation is modeled by rows of Karman vortices superimposed on an inviscid uniform flow. The vortex-induced vibration problem is modeled by a linear cascade composed of five turbine blades and the coupled Euler and structural dynamics equations are numerically solved using a time-marching boundary element technique. The analysis can be applied to any blade geometries; it is not limited to the blade geometry considered here. Two major design parameters have been identified; the ratio of blade spacing to blade chord length s/c of the stator, and the normalized frequency parameter c/d which is related to the wake passing frequency of the rotor. For a rigid cascade, it is found that aerodynamic resonance prevails at the resonant c/d values corresponding to an isolated blade while s/c is responsible for the level of the aerodynamic response. If the central blades were elastic, the parameter s/c plays a different role in the fluid-structure interaction problem. With a c/d that could lead to structural resonance for an isolated blade, changing s/c would stabilize the aerodynamic and structural response of the elastic blade in a cascade. On the contrary, an improper choice of s/c might turn the elastic blade response into structural resonance even though the oncoming c/d is non-resonant. The results of the nonlinear effects of c/d and s/c could be used together with the Campbell diagram to obtain an improved HCF design of rotor-stator pair. (C) 2007 Elsevier Ltd. All rights reserved. C1 Hong Kong Polytech Univ, Dept Mech Engn, Kowloon, Hong Kong, Peoples R China. RP Leung, RCK, Hong Kong Polytech Univ, Dept Mech Engn, Kowloon, Hong Kong, Peoples R China. EM yllau@spinmaster.com.hk mmrleung@inet.polyu.edu.hk mmmcso@polyu.edu.hk CR *AM SOC TEST MAT A, 1985, STAND PRACT CYCL COU *ROLLS ROYC PIC, 1986, JET ENG, P23 CICATELLI G, 1997, J TURBOMACH, V119, P810 DOBRZYNSKI W, 1993, J SOUND VIB, V163, P123 DOWLING NE, 1983, J ENG MATER-T ASME, V105, P206 DOWNING SD, 1982, INT J FATIGUE, V4, P31 EMERY JC, 1958, 1368 NACA FLEETER S, 1981, ASME, V103, P59 FOTTNER L, 1989, AGARD LECT SERIES, P167 FUNAZAKI K, 1989, P 5 INT S, P287 HARRIS WJ, 1962, DESIGNING FATIGUE HILL PG, 1992, MECH THERMODYNAMICS, P179 HODSON HP, 1985, J ENG GAS TURB POWER, V107, P337 HODSON HP, 1998, J TURBOMACH, V120, P276 HODSON HP, 2005, ANNU REV FLUID MECH, V37, P71, DOI 10.1146/annurev.fluid.37.061903.175511 JADIC I, 1998, J FLUID STRUCT, V12, P631 JOHNSEN IA, 1965, SP36 NASA KACKER SC, 1982, ASME, V104, P111 KOCH PJ, 2001, J PROPUL POWER, V17, P474 KORAKIANITIS T, 1992, J TURBOMACH, V114, P114 LAU YL, 2003, THESIS HONG KONG POL LAU YL, 2004, J FLUID STRUCT, V19, P1061, DOI 10.1016/j.jfluidstructs.2004.06.007 LEUNG RCK, 2001, J SOUND VIB, V245, P217 LUK KF, 2004, AIAA J, V42, P899 MELLOR GL, 1957, 38 GAS TURB LAB MELLOR GL, 1958, SERIES CASCADE DATA, V65 NAUASCHER E, 1994, FLOW INDUCED VIBRATI OTIS CE, 2001, AIRCRAFT GAS TURBINE, CH4 PROBASCO DP, 2000, INT J TURBO JET ENG, V17, P197 RAO TS, 1991, TURBOMACHINE BLADE V, P3 SANDERS AJ, 1999, J PROPUL POWER, V15, P650 SANDERS AJ, 2000, J PROPUL POWER, V16, P421 SIEVERDING CH, 1990, J TURBOMACH, V112, P181 SIEVERDING CH, 2003, J TURBOMACH, V125, P298, DOI 10.1115/1.1539057 SO RMC, 1999, J FLUID STRUCT, V13, P519 SPEZIALE CG, 1986, J FLUIDS ENG, V108, P304 TOPOL DA, 1993, J AIRCRAFT, V30, P728 TREAGER IE, 1979, AIRCRAFT GAS TURBINE, P12 WILSON DG, 1998, DES HIGH EFF TURB GA WISLICENUS GF, 1965, FLUID MECH TURBOMACH, V1 YILBAS BS, 1998, COMPUT METHOD APPL M, V158, P143 YU WS, 1995, J FLUID ENG-T ASME, V117, P639 NR 42 TC 0 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 6 PY 2007 VL 307 IS 3-5 BP 698 EP 719 PG 22 SC Acoustics; Engineering, Mechanical; Mechanics GA 220DN UT ISI:000250137200017 ER PT J AU Nijssen, RPL van Wingerde, AM van Delft, DRV AF Nijssen, R. P. L. van Wingerde, A. M. van Delft, D. R. V. TI Wind turbine rotor blade materials: Estimating service lives SO SAMPE JOURNAL LA English DT Article ID FATIGUE AB x Wind turbine rotor blades experience in excess of 10(7) significant load cycles, which makes them an exceptionally demanding application of composites, in terms of fatigue loading. Typical wind turbine rotor blade composites were tested in fatigue, and strength after fatigue. These experiments provide input data for strength degradation models. Such models can be used for life and strength prediction. In addition, load spectrum tests were done, to investigate possible effects of load sequence on fatigue life. These experimental data provide important information on wind turbine composite fatigue behaviour. Life estimation models are specified using the experimental data, and spectrum load test results are compared with theoretical life estimates. C1 Knowledge Ctr Wind Turbine Mat & Construct WMC, Wieringerwerf, Netherlands. RP Nijssen, RPL, Knowledge Ctr Wind Turbine Mat & Construct WMC, Wieringerwerf, Netherlands. CR *AM SOC TEST MAT, 1996, ASTM3479D3479M96 *ISO INT STAND, 2003, 13003 ISO ANDERSONS J, 1997, P ICCM 11, P135 GERMANISCHER L, 2003, RULES REGULATIONS, P5 MANDELL JF, 1997, SAND973002 NIJSSEN RPL, 2004, OBTCR018 SCHAFF JR, 1997, J COMPOS MATER, V31, P128 SOKER H, 2004, NEW WISPER CREATING TANHAVE AA, 1988, P EUR COMM WIND EN C VANDELFT DRV, 1997, P 1997 ASME WIND EN, P180 WAHL NK, 2001, THESIS MONTANA STATE WAHL NK, 2002, P ASME AIAA WIND EN WHITWORTH HA, 2000, COMPOS STRUCT, V48, P261 YAO WX, 2000, COMPOS SCI TECHNOL, V60, P59 NR 14 TC 0 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 0091-1062 J9 SAMPE J JI Sampe J. PD MAR-APR PY 2007 VL 43 IS 2 BP 7 EP 15 PG 9 SC Engineering, Multidisciplinary; Materials Science, Multidisciplinary GA 196WS UT ISI:000248514300003 ER PT J AU Mokadem, S Bezencon, C Hauert, A Jacot, A Kurz, W AF Mokadem, S. Bezencon, C. Hauert, A. Jacot, A. Kurz, W. TI Laser repair of superalloy single crystals with varying substrate orientations SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID STRAY GRAIN FORMATION; NI-BASE SUPERALLOY; MICROSTRUCTURAL DEVELOPMENT; SOLIDIFICATION PROCESSES; WELDS; MODEL; PREDICTION; DEPOSITION; ALLOYS; GROWTH AB The casting and repair of single-crystal gas turbine blades require specific solidification conditions that prevent the formation of new grains, equiaxed or columnar, ahead of the epitaxial columnar dendrites. These conditions are best determined by microstructure modeling. Present day analytical models of the column ar-to-equiaxed transition (CET) relate the microstructure to local solidification conditions (temperature gradient and interface velocity) without taking into account the effects of (1) a preferred growth direction of the columnar dendrites and (2) a growth competition between columnar grains of different orientations. In this article, the influence of these effects on the grain structure of nickel-base superalloy single crystals, which have been resolidified after laser treatment or directionally cast, is determined by experiment and by analytical and numerical modeling. It is shown that two effects arise for the case of a nonzero angle between the local heat flux direction and the preferred dendrite growth axis: (1) the regime of equiaxed growth is extended and (2) a loss of the crystal orientation of the substrate often occurs by growth competition of columnar grains leading to an "oriented-to-misoriented transition" (OMT). The results are essential for the definition of the single-crystal processing window and are important for the service life extension of expensive components in land-based or aircraft gas turbines. C1 Ecole Polytech Fed Lausanne, Inst Mat, CH-1015 Lausanne, Switzerland. Siemens Power Generat, D-45473 Mulheim, Germany. Novelis Switzerland SA, CH-3960 Sierre, Switzerland. RP Jacot, A, Ecole Polytech Fed Lausanne, Inst Mat, CH-1015 Lausanne, Switzerland. EM alain.jacot@epfl.ch CR BEZENCON C, 2002, P MAT ADV POW ENG M, P503 BEZENCON C, 2002, THESIS I MAT LAUSANN BEZENCON C, 2003, SCRIPTA MATER, V49, P705, DOI 10.1016/S1359-6462(03)00369-5 BOBADILLA M, 1988, J CRYST GROWTH, V89, P531 DAVID SA, 1997, SCI TECHNOL WELD JOI, V2, P79 DOBLER S, 1998, I MAT ECOLE POLYTECH ESAKA H, 1986, THESIS I MAT LAUSANN GANDIN CA, 1994, ACTA METALL MATER, V42, P2233 GANDIN CA, 1997, ACTA MATER, V45, P2187 GANDIN CA, 1999, METALL MATER TRANS A, V30, P3153 GAUMANN M, 1997, MAT SCI ENG A-STRUCT, V226, P763 GAUMANN M, 1997, P LAS ASS NET SHAP E, P651 GAUMANN M, 1999, MAT SCI ENG A-STRUCT, V271, P232 GAUMANN M, 2001, ACTA MATER, V49, P1051 HUNT JD, 1984, MATER SCI ENG, V65, P75 JANSSON B, 1993, J PHASE EQUILIB, V14, P557 KURZ W, 1986, ACTA METALL, V34, P823 KURZ W, 1998, FUNDAMENTALS SOLIDIF KURZ W, 2001, ADV ENG MATER, V3, P443 MOKADEM S, 2004, SOLIDIFICATION PROCE, P67 MOKADEM S, 2004, THESIS I MAT LAUSANN PARK JW, 2003, J APPL PHYS, V94, P4203, DOI 10.1063/1.1602950 PICASSO M, 1994, METALL MATER TRANS B, V25, P281 PORTER DA, 1992, PHASE TRANSFORMATION, P118 RAPPAZ M, 1989, METALL TRANS A, V20, P1125 RAPPAZ M, 1993, ACTA METALL MATER, V41, P345 RAPPAZ M, 1999, ACTA MATER, V47, P3205 RAPPAZ M, 2003, METALL MATER TRANS A, V34, P467 SCHNELL A, 2004, UNPUB ALSTOM POWER VITEK JM, 2005, ACTA MATER, V53, P53, DOI 10.1016/j.actamat.2004.08.039 VITEK JN, 1997, SCI TECHNOL WELD JOI, V2, P109 WANG N, 2004, ACTA MATER, V52, P3173, DOI 10.1016/j.actamat.2004.03.047 NR 32 TC 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 2007 VL 38A IS 7 BP 1500 EP 1510 PG 11 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 196VW UT ISI:000248511300015 ER PT J AU Gordon, AP Trexler, MD Neu, RW Sanders, TJ McDowell, DL AF Gordon, Ali P. Trexler, Matthew D. Neu, Richard W. Sanders, Thomas J. McDowell, David L. TI Corrosion kinetics of a directionally solidified Ni-base superalloy SO ACTA MATERIALIA LA English DT Article DE directionally solidified; Ni-base superalloys; low cycle fatigue; syngas; oxidation ID LOW-CYCLE FATIGUE; THERMOMECHANICAL FATIGUE; LIFE PREDICTION; BEHAVIOR; TEMPERATURE; OXIDATION; CREEP; SPALLATION; MAR-M247 AB A variety of experiments were carried out to characterize the corrosion kinetics of a longitudinally oriented directionally solidified Nibase superalloy, DS GTD- 111, commonly applied as a first- and second-stage blading material in electric power generation gas-powered turbines. Under operating environments, the airfoil sections of turbine blades sustain surface-initiated damage due to the superimposed centrifugal stresses, elevated temperature and presence of corrosive reactants in the environment. As a consequence, surface cracking curtails the service lives of such components. To thoroughly characterize the stress-free and stress-assisted kinetics of diffusion and cyclic oxide rupture, several types of experiments are conducted: low cycle fatigue, thermomechanical fatigue, and thermogravimetric analysis, among others. A key goal of this study is to provide data necessary for the development of diffusion kinetics models. Accordingly, the study is divided into two parts: stress-free diffusion and stress-assisted rupture. Models are developed for each of these conditions. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Univ Cent Florida, Dept Mech Mat & Aerosp Engn, Orlando, FL 32828 USA. Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. RP Gordon, AP, Univ Cent Florida, Dept Mech Mat & Aerosp Engn, Orlando, FL 32828 USA. EM apgordon@mail.ucf.edu CR ANTOLOVICH SD, 1981, METALL TRANS A, V12, P473 BECK T, 2002, TEMPERATURE FATIGUE, P115 BIRKS N, 1983, INTRO HIGH TEMPERATU BOISMIER DA, 1990, J ENG MATER-T ASME, V112, P68 BOUHANEK K, 1997, MATER SCI FORUM 1-2, V251, P33 DAS DK, 2003, MATER SCI TECH-LOND, V19, P695, DOI 10.1179/026708303225001975 EVANS HE, 1994, MATER HIGH TEMP, V12, P219 EVANS HE, 1997, SURF COAT TECH, V94, P27 GORDON AP, 2006, THESIS GEORGIA I TEC KHANNA AS, 2002, INTRO HIGH TEMPERATU KOSTER A, 2002, PHYS BASE MODEL LI MH, 2003, OXID MET, V59, P591 MALPERTU JL, 1990, METALL TRANS A, V21, P389 NATEGH S, 2003, MAT SCI ENG A-STRUCT, V339, P103 NEU RW, 1989, METALL TRANS A, V20, P1755 NICHOLLS JR, 1996, MAT HIGH TEMP, V14, P5 REMY L, 1993, ASTM STP, V1186, P3 REUCHET J, 1983, METALL TRANS A, V14, P141 SEHITOGLU H, 1990, J ENG MATER-T ASME, V112, P80 SHENOY MM, 2005, J ENG MATER-T ASME, V127, P325, DOI 10.1115/1.1924560 SRINIVAS N, 1995, EVOL COMPUT, V2, P3 VALERIO P, 1994, SCRIPTA METALL MATER, V30, P1269 VASSEUR E, 1994, MAT SCI ENG A-STRUCT, V184, P1 WRIGHT PK, 1988, ASTM STP, V942, P558 ZAMRIK SY, 2000, AM SOC TEST MATER, V1371, P119 NR 25 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN PY 2007 VL 55 IS 10 BP 3375 EP 3385 PG 11 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 174QE UT ISI:000246956600007 ER PT J AU Tsai, PC Lee, JH Hsu, CS AF Tsai, P. C. Lee, J. H. Hsu, C. S. TI Hot corrosion behavior of laser-glazed plasma-sprayed yttria-stabilized zirconia thermal barrier coatings in the presence of V2O5 SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE thermal barrier coatings; hot corrosions laser-glazing; plasma-sprayed; zirconia ID CERAMIC COATINGS; CYCLIC OXIDATION; FAILURE; PERFORMANCE; RESISTANCE; MECHANISMS; TESTS; MICROSTRUCTURES AB Thermal barrier coatings (TBCs) are now currently used in gas turbine engines' blades and vanes. A typical duplex TBCs system comprises of a plasma-sprayed thermally insulating ZrO2 alloy top coat applied over an oxidation-resistant MCrAlY (M=Ni and/or Co) bond coat. In this investigation, the substrates of Hastelloy-X superalloy coupons were first sprayed with a Ni-22Cr-10Al-1Y bond coat and then with an yttria-stabilized zirconia (YSZ) top coat in which the yttria contents were varied from 6.1 wt.% to 19.5 wt.%. After that, the plasma-sprayed yttria-stabilized zirconia/MCrAlY TBCs were glazed using a pulsed CO, laser. The hot corrosion resistance of plasma-sprayed and laser-glazed zirconia thermal barrier coatings at 910 degrees C was investigated using coupons on which were deposited Na2SO4 and/or V2O5. The results of the high temperature corrosion tests showed that the lifetimes of the plasma-sprayed TBCs with different yttria content were all increased about fourfold by laser-glazing in the V2O5 salt contained test. The lifetime decreased with increasing the amount of deposited V2O5 salt. The X-ray diffraction showed that the reaction between yttria (Y2O3) and V2O5 produced YVO4, leaching Y2O3 from the YSZ and causing progressive cubic, tetragonal to monoclinic phase destabilization transformation. The failure of the TBCs was initiated and propagated mainly within the top coat, near the top coat-bond coat interface. Both adding Na2SO4 and a reaction between Na2SO4 and the bond coat can probably reduce the strain accommodation of the top coat. There are no significant corrosion cyclic life differences for TBC with various YSZ top coats for both plasma-sprayed and laser-glazed TBC. (C) 2006 Elsevier B.V. All rights reserved. C1 Natl Formosa Univ, Dept Mat Sci & Engn, Huwei, Yunlin, Taiwan. RP Tsai, PC, Natl Formosa Univ, Dept Mat Sci & Engn, 64 Wenhua Rd, Huwei, Yunlin, Taiwan. EM pc6996@ms16.hinet.net CR *JCPDS, 701281 JCPDS ADAMSKI A, 1986, ADV THERMAL SPRAYING, P555 BERNDT CC, 1983, THIN SOLID FILMS, V108, P427 BRATTON RJ, 1980, THIN SOLID FILMS, V73, P429 BRUCE RW, 1998, TRIBOL T, V41, P399 FISCHMAN GS, 1985, CERAM ENG SCI P, V9, P908 GELL M, 1999, SURF COAT TECH, V120, P53 HODGE PE, 1980, THIN SOLID FILMS, V73, P447 IWAMOTO N, 1988, SURF COAT TECH, V34, P59 JASIM KM, 1988, J MATER SCI LETT, V7, P1307 JASIM KM, 1989, LASER MAT PROCESSING, P17 JONES RL, 1989, SURF COAT TECH, V37, P271 MCKEE DW, 1980, THIN SOLID FILMS, V73, P439 MILLER RA, 1981, ADV CERAM, V3, P241 MILLER RA, 1982, THIN SOLID FILMS, V95, P265 MILLER RA, 1984, THIN SOLID FILMS, V119, P195 NAGARAJ BA, 1990, J ENG GAS TURB POWER, V112, P536 NICHOLLS JR, 1999, WEAR, V233, P352 PETITBON A, 1991, SURF COAT TECH, V49, P57 SCHMITTTHOMAS KG, 1999, SURF COAT TECH, V120, P84 SHILLINGTON EAG, 1999, ACTA MATER, V47, P1297 SIVAKUMAR R, 1988, SURF ENG, V4, P127 SUSNITZKY DW, 1988, J AM CERAM SOC, V71, P992 TSAI HL, 1993, MAT SCI ENG A-STRUCT, V161, P145 TSAI HL, 1994, MAT SCI ENG A-STRUCT, V177, P227 TSAI HL, 1995, J MATER ENG PERFORM, V4, P689 TSAI HL, 1995, SURF COAT TECH, V71, P53 TSAI HL, 1998, J MATER ENG PERFORM, V7, P258 TSAI PC, 1993, MAT SCI ENG A-STRUCT, V165, P67 TSAI PC, 2004, SURF COAT TECH, V183, P29, DOI 10.1016/j.surfcoat.0203.08.090 WU BC, 1989, J AM CERAM SOC, V72, P212 WU BC, 1989, MAT SCI ENG A-STRUCT, V111, P201 WU BC, 1989, THIN SOLID FILMS, V172, P185 ZAPLATYNSKY I, 1982, THIN SOLID FILMS, V95, P275 NR 34 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD FEB 26 PY 2007 VL 201 IS 9-11 BP 5143 EP 5147 PG 5 SC Materials Science, Coatings & Films; Physics, Applied GA 168FT UT ISI:000246509400077 ER PT J AU Lvova, E AF Lvova, E. TI A comparison of aging kinetics of new and rejuvenated conventionally cast GTD-111 gas turbine blades SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE aging kinetics; gas turbine blades; rejuvenation; superalloys ID NI-BASE SUPERALLOYS; MICROSTRUCTURAL CHANGES; HEAT-TREATMENT; IN-738 AB Two industrial gas turbine blades made from a conventionally cast Ni-base superalloy GTD-111, one new and the other rejuvenated, were removed from the same machine after a particular operational cycle for an examination in order to determine the effect of rejuvenation on the material's behavior during service. It was found that service-induced changes in the microstructure, such as gamma '-phase coarsening and coalescence, excessive grain-boundary secondary M23C6 carbides formation, and primary MC carbides decomposition, were noticeably more advanced in the rejuvenated blade. The stress-rupture life of the rejuvenated blade decreased significantly compared to that of the new blade after the same number of hours in service. The cause of this decrease appears to be related to a release of additional amounts of carbon and carbide-forming elements into the matrix during rejuvenating heat treatment as a result of the primary MC carbide decomposition. C1 GE Preco, Met Lab, Houston, TX 77073 USA. RP Lvova, E, GE Preco, Met Lab, 17619 Aldine Westfield Rd, Houston, TX 77073 USA. EM evgenia.lvova@ge.com CR BALDAN A, 1995, P C MAT AG COMP LIF, V2, P943 BEDDOES JC, 1980, METALLOGRAPHY, V13, P185 DALEO JA, 1998, J ENG GAS TURBINES P, V120 DURRANDCHARRE M, 1997, MICROSTRUCTURE SUPER HAKL J, 1995, P C MAT AG COMP LIF, V2, P991 KOUL AK, 1988, METALL TRANS A, V19, P2049 LVOV G, 2004, METALL MATER TRANS A, V35, P1669 LVOVA E, 2001, J MATER ENG PERFORM, V10, P299 SIMS CT, 1984, SUPERALLOYS 2, P97 STEVENS RA, 1978, J MATER SCI, V13, P367 STEVENS RA, 1979, 5 INT C AACH GERM AU, V1, P439 STEVENS RA, 1979, MATER SCI ENG, V37, P237 TAWANCY HM, 1994, J MATER SCI, V29, P2445 XUEBING H, 1998, MATER LETT, V36, P210 NR 14 TC 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD APR PY 2007 VL 16 IS 2 BP 254 EP 264 PG 11 SC Materials Science, Multidisciplinary GA 165QQ UT ISI:000246320800020 ER PT J AU Tsai, JI AF Tsai, Jong-Ian TI A new damper scheme to restrict torsional torques on the turbine generator shafts and blades near a HVDC link SO ELECTRICAL ENGINEERING LA English DT Article DE torsional vibration; damper; turbine; HVDC; harmonics ID EXCITER SHAFTS; DC CURRENTS; LIFE EXPENDITURE; FATIGUE; FAULTS AB Due to more various power disturbances occurring in a power system involving a HVDC link, the turbine generator shafts and/or blades are more prone to damage than in general HVAC systems. In this paper, a new mechanical damper scheme based on participation factor approach is proposed to damp torsional torque and prolong the life of turbine mechanism. Two types of torsional damping couplings, inertia damping coupling and elastic damping coupling, are adopted and examined. The optimal type and the optimal location of the damping coupling will be identified and installed to the turbine generator shaft section. The results demonstrate that the best damper may not be installed at the location with the most onerous vibrations but provides satisfactory damping performance on shafts and blades following severe power disturbances in a HVDC link. C1 Kao Yuan Inst Technol, Dept Elect Engn, Kaohsiung 82101, Taiwan. RP Tsai, JI, Kao Yuan Inst Technol, Dept Elect Engn, 1821 Chung Shan Rd,Lu Chu Hsiang, Kaohsiung 82101, Taiwan. EM jitsai@cc.kyu.edu.tw CR 2001, POWER SYSTEM BLOCKSE CHYN C, 1996, IEE P-GENER TRANSM D, V143, P479 FARIED SO, 1997, IEEE T POWER SYST, V12, P875 GONZALEZ AJ, 1984, IEEE T POWER AP SYST, V103, P3218 HAMMONS TJ, 1994, IEEE T ENERGY CONVER, V9, P503 HAMMONS TJ, 1995, IEEE T ENERGY CONVER, V10, P95 HAMMONS TJ, 1997, ELECTR MACH POW SYST, V25, P87 LAMBRECHT D, 1982, IEEE T POWER AP SYST, V101, P3689 LIANG CC, 1993, TAIPOWER ENG J, V538, P35 LIN CH, 2001, IEE P-GENER TRANSM D, V148, P97 PLACEK RJ, 1984, EL3083 EPRI SHI W, 1994, IEEE T POWER SYST, V9, P1457 TSAI JI, 2003, ELECTR POW SYST RES, V65, P135, DOI 10.1016/S0378-7796(02)00220-1 TSAI JI, 2004, IEEE T POWER SYST, V19, P507, DOI 10.1109/TPWRS.2003.820704 TSAO TP, 2000, IEE P-SCI MEAS TECH, V147, P229 NR 15 TC 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0948-7921 J9 ELECTR ENG JI Electr. Eng. PD MAY PY 2007 VL 89 IS 5 BP 377 EP 387 PG 11 SC Engineering, Electrical & Electronic GA 163ZT UT ISI:000246202900004 ER PT J AU Sato, A Aoki, Y Arai, M Harada, H AF Sato, Akihiro Aoki, Yasuhiro Arai, Mikiya Harada, Hiroshi TI Effect of aluminide coating on creep properties of Ni-base single crystal superalloys SO JOURNAL OF THE JAPAN INSTITUTE OF METALS LA Japanese DT Article DE aluminide; nickel-base single crystal superalloys; secondary reaction zone (SRZ); creep-rupture life AB This article compares the creep rupture responses of aluminide coated samples with uncoated ones to elucidate the effect of diffusion layers on resistance against creep. Three Ni-base single crystal superalloys, CMSX-4, TMS-75 and TMS-138, were chosen for present study. Creep specimens had thicknesses ranged from I turn to 4 mm to simulate the varying dimensions across the actual turbine blade. Creep conditions were set at 1060 degrees C-137 MPa and 1100 degrees C-137 MPa. Experimental results indicated that the creep-rupture lives of coated specimens were shorter than those of the bare samples. In particular, the coated TMS-138 specimen with 1 mm thickness had an 86% reduction in creep rupture life. Microstructural observations on coated samples indicated the formation of diffusion zones beneath the coating; a creep life model was then developed to taken account the reduction in load bearing cross sectional area. In conclusions, the creep-rupture lives predicted by the model have shown good agreement with the experimental values. C1 Natl Inst Mat Sci, High Temp Mat Ctr, Tsukuba, Ibaraki 3050047, Japan. Ishikawajima Harima Heavy Ind Co Ltd, Tokyo 1358710, Japan. RP Sato, A, Natl Inst Mat Sci, High Temp Mat Ctr, Tsukuba, Ibaraki 3050047, Japan. CR HARRIS K, 1992, SUPERALLOYS 1992, P297 KOIZUMI Y, 2003, J JPN I MET, V67, P468 KOIZUMI Y, 2004, SUPERALLOYS 2004, P35 LAVIGNE O, 2004, SUPERALLOYS 2004, P667 LOCCI IE, 2004, NASATM2004212920 MATSUOKA Y, 2004, SUPERALLOY 2004, P637 NABARRO FRN, 1995, PHYS CREEP, P241 NARITA T, 2004, 6830827, US PADTURE NP, 2002, SCIENCE, V296, P280 SATO A, 2006, J JPN I MET, V70, P192 SATO A, 2006, METALL MATER TRANS A, V37, P789 SPITZBERG IT, 2001, 6306524, US WALSTON WS, 1996, SUPERALLOYS 1996, P9 WALSTON WS, 2004, SUPERALLOYS 2004, P579 WING RG, 2000, 6080246, US YOKOKAWA T, 1998, P MAT ADV POW ENG 2, P1121 ZHANG JX, 2004, SUPERALLOYS, P189 NR 17 TC 1 PU JAPAN INST METALS PI SENDAI PA 1-14-32 ICHIBANCHO AOBA-KU, SENDAI, 980-8544, JAPAN SN 0021-4876 J9 J JPN INST METAL JI J. Jpn. Inst. Met. PD MAR PY 2007 VL 71 IS 3 BP 320 EP 325 PG 6 SC Metallurgy & Metallurgical Engineering GA 156PB UT ISI:000245660300002 ER PT J AU Gurrappa, I Rao, AS AF Gurrappa, I. Rao, A. Sambasiva TI Thermal barrier coatings for enhanced efficiency of gas turbine engines SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE super alloys; gas turbine engines; hot corrosion; protective coatings ID HOT CORROSION-RESISTANCE; OVERLAY COATINGS; BOND COATINGS; NI-CR; SUPERALLOYS; OXIDATION; IDENTIFICATION; PERFORMANCE; DEGRADATION; COMPONENTS AB In the current paper, an attempt has been made to address the benefit as well as importance of optimisation of thermal barrier coatings system for super alloys after evaluating different thicknesses of ceramic thermal barrier coatings. The thickness of coatings plays a major role in deciding the life of coatings as lower thickness does not provide complete protection and higher thickness causes to reduce the coating life due to adherence problems. Therefore, determination of optimum thickness to obtain improved performance is highly essential. An optimum thickness of thermal barrier coatings has been determined successfully by conducting hot corrosion studies on various thicknesses. The optimised protective coating system enhances the life of super alloy by about six hundred times. The optimum performance of the designed coating system is due to the formation of a continuous and protective layer of a combined alumina and chromia scales. Based on the results, a degradation mechanism is proposed and showed that the protective properties of ceramic coatings are lost due to chemical reactions taking place under hot corrosion conditions. Finally, the necessity of application of optimum thick thermal barrier coatings with compositionally optimised NiCoCrAlY coating, which can protect the gas turbine engine blade materials significantly against both oxidation and hot corrosion conditions, is emphasized. (c) 2006 Elsevier B.V. All rights reserved. C1 Def Met Res Lab, Hyderabad 500058, Andhra Pradesh, India. RP Gurrappa, I, Def Met Res Lab, Po Kanchanbagh, Hyderabad 500058, Andhra Pradesh, India. EM igp1@redifmail.com CR ALI MY, 2001, INT J SOLIDS STRUCT, V38, P3329 BEELE W, 1996, SURF COAT TECH, V86, P41 BRANDL W, 1996, SURF COAT TECH 1, V86, P41 ELIAZ N, 2002, ENG FAIL ANAL, V9, P31 ERDOS E, 1986, OXID MET, V26, P101 FRITSCHER K, 1995, MATER SCI ENG, V190, P86 FRYXELL RE, 1984, CR174683 NASA GALLARDO JM, 2002, WEAR, V252, P264 GURRAPPA I, 1997, J HIGH TEMP MAT SCI, V38, P137 GURRAPPA I, 1998, J MATER SCI LETT, V17, P1267 GURRAPPA I, 1999, J ELECTROCHEM SOC, V48, P187 GURRAPPA I, 1999, J MATER SCI LETT, V18, P1713 GURRAPPA I, 1999, MATER MANUF PROCESS, V50, P353 GURRAPPA I, 2000, MATER MANUF PROCESS, V15, P761 GURRAPPA I, 2001, J MATER SCI LETT, V20, P2225 GURRAPPA I, 2001, SURF COAT TECH, V139, P272 GURRAPPA I, 2003, MATER SCI TECH-LOND, V19, P178, DOI 10.1179/026708303225009382 GURRAPPA I, 2003, OXID MET, V59, P321 GURRAPPA I, 2004, P INT CONV SURF ENG, P115 HOCKING MG, 1986, MAT SCI TECH, V2, P318 KHAJAVI MR, 2004, ENG FAIL ANAL, V11, P589, DOI 10.1016/j.engfailanal.2003.08.010 KNIGHT R, 1998, P 15 INT THERM SPRAY, V2, P1549 KOHL FJ, 1979, P 4 C GAS TURB MAT M, P565 KONTER M, 2001, J MATER PROCESS TECH, V117, P386 LEE EY, 1989, MAT SCI ENG A-STRUCT, V121, P467 LEPRINCE G, 1989, MAT SCI ENG A-STRUCT, V121, P419 LEYENS C, 1997, SURF COAT TECH, V94, P155 LIN W, 1992, SURF COAT TECH, V50, P277 LUTHRA KL, 1980, J ELECTROCHEM SOC, V127, P2202 MISRA AK, 1987, P 10 INT C MET CORR, V4, P3533 MUMM DR, 2001, KEY ENG MAT, V197, P199 NATESAN K, 1987, MATER SCI ENG, V87, P99 RADCLIFF AS, 1987, MATER SCI TECH SER, V3, P554 RHYSJONES TN, 1989, HIGH TEMP TECHNOL, V7, P73 SAUNDERS SRJ, 1984, THIN SOLID FILMS, V119, P247 SINGER RF, 1987, MATER SCI TECH SER, V3, P726 SMEGGIL JG, 1980, 159747 NASA CR SOECHTING FO, 1999, J THERM SPRAY TECHN, V8, P505 STRAWBRIDGE A, 1997, MATER SCI FORUM 1-2, V251, P365 STRINGER J, 1987, MATER SCI TECH SER, V3, P482 VASSEN R, 2001, MAT SCI ENG A-STRUCT, V303, P100 WORTMAN DJ, 1989, MAT SCI ENG A-STRUCT, V121, P433 NR 42 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 4 PY 2006 VL 201 IS 6 BP 3016 EP 3029 PG 14 SC Materials Science, Coatings & Films; Physics, Applied GA 144YF UT ISI:000244831800124 ER PT J AU Schreck, SJ Robinson, MC AF Schreck, Scott J. Robinson, Michael C. TI Horizontal axis wind turbine blade aerodynamics in experiments and modeling SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article DE aerodynamics; modeling; wind energy; wind tunnels ID DYNAMIC STALL; PREDICTION; FLIGHT; ROTOR; LOADS AB Turbine aerodynamics remains a challenging and crucial research area for wind energy. Blade aerodynamic forces responsible for Power production must be augmented to maximize energy capture. At the same time, adverse aerodynamic loads that fatigue turbine components need to be mitigated to extend machine service life. Successful resolution of these conflicting demands and continued cost of energy reduction require accurate blade aerodynamic models. This, in turn, depends on clear physical understanding and reliable numerical modeling of rotational augmentation and dynamic stall, the two phenomena principally responsible for amplified turbine blade aerodynamic loads. The current work examines full-scale turbine blade aerodynamic measurements and current modeling methodologies to better understand the physical and numerical attributes that determine model performance. C1 Natl Renewable Energy Lab, Natl Wind Technol Ctr, Golden, CO 80401 USA. RP Schreck, SJ, Natl Renewable Energy Lab, Natl Wind Technol Ctr, Golden, CO 80401 USA. EM scott_schreck@nrel.gov michael_robinson@nrel.gov CR *DEWI, WIND EN 2006 MARK AS *EX COMM INT EN AG, 2001, LONG TERM RES DEV NE *WHIT HOUS NAT EC, 2006, ADV EN IN, P13 BANKS WHH, 1963, AIAA J, V1, P941 BARNSLEY M, 1992, J WIND ENG IND AEROD, V39, P11 BIERBOOMS W, 1992, J WIND ENG IND AEROD, V39, P23 BUTTERFIELD C, 1991, NRELTP2574510 BUTTERFIELD CP, 1992, NRELTP2574655 CARR LW, 1988, J AIRCRAFT, V25, P6 CORRIGAN J, 1994, AM HEL SOC AER SPEC CORTEN G, 2001, P EUR WIND EN C JUN, P466 DU Z, 2001, AIAA980021 EGGERS A, 1992, 11 ASME WIND EN S HO FREYMUTH P, 1988, J AIRCRAFT, V25, P971 HAND M, 2001, NRELTP50029955 HAND MM, 2001, NRELTP50029491 HANSEN AC, 1990, J SOL ENERG-T ASME, V112, P310 HIMMELSKAMP H, 1950, THESIS M PLANCK I GO HUYER SA, 1996, AIAA J, V34, P1410 JOHNSON W, 1980, HELICOPTER THEORY, P893 LEISHMAN JG, 2006, PRINCIPLES HELICOPTE LORBER P, 1992, R929583256 UTRC MADSEN H, 1990, WIND ENG, V14, P405 MCCROSKEY W, 1968, AIAA J, V6, P1919 MCCROSKEY WJ, 1971, D6321 NASA TN MCCROSKEY WJ, 1977, J FLUIDS ENG, P8 PIERCE K, 1995, J SOL ENERG-T ASME, V117, P200 PIZIALI R, 1994, 4632 NASA TM RAMSAY RR, 1995, NRELTP4427817 ROBINSON M, 1988, AIAA 26 AER SCI M JA ROBINSON M, 1995, 33 AER SCI M EXH JAN RONSTEN G, 1992, J WIND ENG IND AEROD, V39, P105 SCHRECK S, 1991, AIAA 22 FLUID DYN PL SCHRECK S, 2000, WIND ENERGY, V3, P215 SCHRECK S, 2003, AIAA20030520 SCHRECK S, 2007, WIND ENERGY, V10 SCHRECK SJ, 1994, J AIRCRAFT, V31, P899 SHIPLEY D, 1994, NRELTP4417080 SHIPLEY D, 1995, NRELTP4426912 SIMMS D, 1999, NRELTP50025950 SIMMS D, 1999, NRELTP50027599 SNEL H, 1991, 4 IEA S AER WIND TUR SNEL H, 1992, 18 EUR ROT FOR AV FR SNEL H, 1994, ECNC93052 NETH EN RE TANGLER J, 1997, NRELCP44023258 TISHLER C, 2006, WINDPOWER MON APR, P70 TRAN CT, 1981, VERTICA, V5, P35 ZELL P, 1993, 103920 NASA TM NR 48 TC 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8969 J9 IEEE TRANS ENERGY CONVERS JI IEEE Trans. Energy Convers. PD MAR PY 2007 VL 22 IS 1 BP 61 EP 70 PG 10 SC Energy & Fuels; Engineering, Electrical & Electronic GA 144MI UT ISI:000244799800008 ER PT J AU Marahleh, G Kheder, ARI Hamad, HF AF Marahleh, G. Kheder, A. R. I. Hamad, H. F. TI Creep-life prediction of service-exposed turbine blades SO MATERIALS SCIENCE LA English DT Article AB We study the possibility of prediction of the service life of gas-turbine blades made of nickel alloys according to the results of accelerated testing of specimens cut out from these blades. The predictions are carried out with the help of two methods: by using the Larson-Miller parameter and according to Robinson's rule. It is shown that the predictions performed by using the Larson-Miller parameter on the basis of extrapolation of the data of accelerated tests are possible but give underestimated results for the durations of service life greater than 80,000h, which is explained by the changes in the microstructure of the material in the course of long-term operation of the blades. C1 Al Balqa Appl Univ, Fac Engn, Dept Mat & Met Engn, Al Salt, Jordan. RP Marahleh, G, Al Balqa Appl Univ, Fac Engn, Dept Mat & Met Engn, Al Salt, Jordan. CR *BS, 1969, 3500 BS 1 BARBOSA C, 2003, ACTA MACROSCOPICA SC, V12, P227 CASTILLO R, 1986, P C HIGH TEMP ALL GA, P1395 CASTILLO R, 1986, P C NICK MET, V11, P261 CASTILLO R, 1987, J ENG GAS TURB POWER, V109, P99 HART RV, 1976, J METALS TECHNOLOGY, V1 LARSON FR, 1952, T ASME, V74, P765 MEYERS MA, 1999, MECH BEHAV MAT ULRICH K, 2004, MAT RES, V17, P1 WALSER B, 1979, P C HEAT MASS TRANSF, P673 XU Y, 1999, MAT SCI ENG A-STRUCT, V260, P48 NR 11 TC 0 PU CONSULTANTS BUREAU/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1068-820X J9 MATER SCI-ENGL TR JI Mater. Sci. PD JUL-AUG PY 2006 VL 42 IS 4 BP 476 EP 481 PG 6 SC Materials Science, Multidisciplinary GA 145GP UT ISI:000244853600006 ER PT J AU Lemco, I AF Lemco, Ian TI Wittgenstein's aeronautical investigation SO NOTES AND RECORDS OF THE ROYAL SOCIETY LA English DT Article DE Wittgenstein; aviation history; jet engines AB After a rigorous German education in the physical sciences, young Ludwig Wittgenstein entered Manchester University as an aeronautical engineering research student. There he devised and patented a novel aero-engine employing an airscrew propeller driven by blade tip-jets. Within the context of the growth of English aviation during the first half of the twentieth century (including the contributions of many Fellows of the Royal Society) and taking into account related aspects of his life, this paper examines an unfulfilled engineering aspiration. In enlarging upon what Wittgenstein might have accomplished during his stay at Manchester, it contrasts his invention with later comparable proven designs, albeit applied to hybrid rotorcraft. His engine employed centrifugal flow compression and arguably was a precursor of Sir Frank Whittle's gas turbine. In conclusion, reasons are given for Wittgenstein's departure from Manchester. RP Lemco, I, 4-21 East Bank, London N16 5RG, England. EM ilemco@theiet.org CR L WITTGENSTEIN EARLY 1957, AEROPLANE 1115, P10 1961, MANCHESTER GUAR 0324 ANDERSON JD, 1997, HIST AERODYNAMICS BOLOBUS B, 1986, LITTLEWOODS MISCELLA, P6 BRACE ES, 1909, Q J R MET SOC, V35, P31 BRODA E, 1983, L BOLTZMANN MAN PSYC, P33 ECCLES W, 1963, HERMATHENA, V97, P57 FORT A, 2003, LIFE F LINDEMANN, P60 GARFIELD M, W MAYS GOODSTEIN RL, 2002, L WITTGENSTEIN PHILO, P271 HERSCHEL H, 2004, AERONAUTICAL RES GER, P304 HISLP GJ, 1958, 7 HEL ASS GREAT BRIT JANICK A, 1973, WITTGENSTEINS VIENNA, P174 LAMBERMONT PM, 1970, HELICOPTERS AUTOGYRO, P295 LOW AR, 1923, J R AERONAUT SOC, V27, P38 MACKERSEY I, 2003, WRIGHT BROTHERS MACKOWER W, 1909, Q J R MET SOC, V35, P7 MAYS W, 1955, MIND, V64, P247 MAYS W, 1967, L WITTGENSTEIN MAN H, P79 MAYS W, 1980, P 4 INT WITTG S KIRC, P171 MCGUINNESS B, 1988, WITTGENSTEIN LIFE, V1, P69 MONK R, 1990, L WITTGENSTEIN DUTY, P33 NAHUM A, 2004, F WHITTLE INVENTION, P3 NELSON WC, 1944, AEROPLANE PROPELLER NORMAN M, 1958, L WITTGENSTEIN MEMOI, P4 PELHAM D, 1976, PENGUIN BOOK KITES RADOK R, 1980, 2 J COOK U N QUEENSL RUSSELL B, 1955, MIND, V64, P31 STEPAN A, 1949, J HELICOPTER SOC GB, V3, P141 STEPAN A, 1958, J R AERONAUT SOC, V62, P123 VONWRIGHT GH, 1992, PORTRAIT WITTGENSTEI WEICK FE, 1930, AIRCRAFT PROPELLER D WITTGENSTEIN L, 1910, 27087 WUCHTEL K, 1979, L WITTGENSTEIN SELBS NR 35 TC 0 PU ROYAL SOCIETY PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0035-9149 J9 NOTES REC ROY SOC JI Notes Rec. R. Soc. PD JAN 22 PY 2007 VL 61 IS 1 BP 39 EP 51 PG 13 SC History & Philosophy Of Science GA 133RL UT ISI:000244030400005 ER PT J AU Moller, BF Genrup, M Assadi, M AF Fredriksson Moller, Bjorn Genrup, Magnus Assadi, Mohsen TI On the off-design of a natural gas-fired combined cycle with CO2 capture SO ENERGY LA English DT Article DE CO2 capture; combined cycles; off-design AB During the last 15 years cycles with CO, capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO, capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively Studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a novel strategy with the possibility of longer life of gas turbine blading, with marginal loss in efficiency. The off-design performance of the combined cycle is modelled in a rigorous Way using a gas turbine performance deck, while the boiler is calculated using simplified correlations for oft-design heat transfer and pressure drop. The steam turbine calculation is based on verified models for the flow-pressure-efficiency relations, whilst the steam condenser is based oil the HEI method. (c) 2006 Elsevier Ltd. All rights reserved. C1 Lund Univ, Fac Engn, Dept Energy Sci, SE-22100 Lund, Sweden. RP Moller, BF, Lund Univ, Fac Engn, Dept Energy Sci, POB 118, SE-22100 Lund, Sweden. EM bjorn.fredriksson@vok.lth.se CR *DIN, 1975, 1943 DIN *HEAT EXCH I, 1984, HEI STAND STEAM SURF *INT EN AG, 2005, KEY EN WORLD STAT 20 ALIE C, 2005, ENERG CONVERS MANAGE, V46, P475, DOI 10.1016/j.enconman.2004.03.003 BECKMANN G, 1963, THESIS DRESDEN CORDES G, 1963, STROMUNGSTECHNIK GAS COTTON KC, 1998, EVALUATING IMPROVING HERZOG H, 2004, ENCY ENERGY JORDAL K, 2005, INT J GREEN ENERGY, V2, P167, DOI 10.1081/GE-200058975 KIM TS, 2004, ENERGY, V29, P71, DOI 10.1016/S0360-5442(03)00157-9 KOHL AL, 1997, GAS PURIFICATION KOSTYUK A, 1998, STEAM GAS TURBINES KVAMSDAL HM, 2004, P 7 INT C GREENH GAS LORENZ M, THESIS LUND I TECH MOUSTAPHA H, 2003, AXIAL RADIAL TURBINE ROBERTS CA, 2004, P 7 INT C GREENH GAS SHIN JY, 2002, ENERGY, V27, P1085 SMITH D, 2002, MODERN POWER SYS NOV STEVENSON JD, 1995, J ENG GAS TURB POWER, V117, P38 STULTZ SC, STEAM ITS GENERATION TRUEDSSON M, THESIS LUND I TECH NR 21 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD APR PY 2007 VL 32 IS 4 SI Sp. Iss. SI BP 353 EP 359 PG 7 SC Thermodynamics; Energy & Fuels GA 129PP UT ISI:000243741700015 ER PT J AU Mendis, BG Tryon, B Pollock, TM Hemker, KJ AF Mendis, B. G. Tryon, B. Pollock, T. M. Hemker, K. J. TI Microstructural observations of as-prepared and thermal cycled NiCoCrAlY bond coats SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE NiCoCrAlY bond coat; phase transitions; diffusion; transmission electron microscopy ID MARTENSITIC-TRANSFORMATION; BARRIER COATINGS; ALLOYS; EVOLUTION; SYSTEMS AB Microstructures of as-prepared and 1100 degrees C/100 h isothermally annealed NiCoCrAlY bond coat specimens as well as a bond coat obtained from an end of life turbine blade were characterized with TEM. In all specimens the gamma grains were observed to consist of fine gamma precipitates, which form during cooling and are unstable at the higher operating temperatures. The beta grains present in the as-prepared specimens were observed to transform to L1(0) martensite in the 1100 degrees C/100 h isothermally annealed specimen. As a result of substrate-bond coat interdiffusion the M-s temperature increases during thermal cycling due to an increase in Ni and decrease in the Cr concentrations of the beta-phase. The turbine blade bond coat was also found to contain Cr and Co-rich sigma-phase precipitates. (c) 2006 Elsevier B.V All rights reserved. C1 Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD USA. Univ Michigan, Dept Mat Sci, Ann Arbor, MI 48109 USA. RP Hemker, KJ, Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD USA. EM hemker@jhu.edu CR ACHAR DRG, 2004, SURF COAT TECH, V187, P272, DOI 10.1016/j.surfcoat.2004.02.018 BAUFELD B, 2004, MAT SCI ENG A-STRUCT, V384, P162, DOI 10.1016/j.msea.2004.05.052 BAUFELD B, 2005, SURF COAT TECH, V199, P49, DOI 10.1016/j.surfcoat.2004.06.014 CHAKRAVORTY S, 1976, METALL T A, V7, P569 CHEN MW, 2003, ACTA MATER, V51, P4279, DOI 10.1016/S1359-6454(03)00225-6 CHEN MW, 2003, METALL MATER TRANS A, V34, P2289 CHEN MW, 2003, SURF COAT TECH, V163, P25 DUPIN N, 2001, SCAND J METALL, V30, P184 ENAMI K, 1978, SCRIPTA METALL, V12, P223 EVANS AG, 2001, PROG MATER SCI, V46, P249 GLYNN ML, 2004, METALL MATER TRANS A, V35, P2279 HORNBOGEN E, 1967, Z METALLKD, V58, P842 KAINUMA R, 1996, METALL MATER TRANS A, V27, P2445 PADTURE NP, 2002, SCIENCE, V296, P280 RAE CMF, 2001, ACTA MATER, V49, P4113 REYNAUD F, 1977, SCRIPTA METALL, V11, P765 ROBERTSON IM, 1983, PHILOS MAG A, V48, P421 ROWLAND LJ, 2005, THESIS U MICHIGAN SAUNDERS N, 2000, NI DATA INFORM THERM TRYON B, UNPUB ZHANG LC, 2005, PHYS METALL MAT SCI, V36, P43 ZHANG Y, 2003, SURF COAT TECH, V163, P19 NR 22 TC 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 20 PY 2006 VL 201 IS 7 BP 3918 EP 3925 PG 8 SC Materials Science, Coatings & Films; Physics, Applied GA 121HW UT ISI:000243149700020 ER PT J AU Wei, RH Langa, E Rincon, C Arps, JH AF Wei, Ronghua Langa, Edward Rincon, Christopher Arps, James H. TI Deposition of thick nitrides and carbonitrides for sand erosion protection SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE thick coatings; nanocomposites; erosion resistance; magnetron sputtering ID MAGNETRON-SPUTTERED DEPOSITION; TITANIUM NITRIDE; HIGH-TEMPERATURE; HARD COATINGS; PVD COATINGS; PERFORMANCE; WEAR; NANOCOMPOSITES; COMPOSITES; RESISTANCE AB Thick nitrides (ZrN, CrN and TiN) and carbonitrides (ZrSiCN and TiSiCN) have been deposited using a Plasma Enhanced Magnetron Sputtering (PEMS) technique. The technique combines a conventional magnetron sputtering and an independently generated plasma from which high current density can be obtained. By using heavy ion bombardment prior to and during deposition to increase the coating adhesion and limit columnar growth, single-layered thick nitrides of ZrN, CrN, and TiN coatings up to about 80 mu m and thick carbonitride coatings of ZrSiCN and TiSiCN about 30 mu m have been obtained. In this paper, we will discuss the deposition technology and the properties of the thick coatings. Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS), and X-Ray Diffractometfy (XRD) were used to study the microstructure and morphology of these coatings. Nanoindentation was conducted to determine the hardness and Young's modulus, while sand erosion tests were conducted to rank the erosion resistance of the coatings. It was observed that TiSiCN rendered the best erosion resistance nearly 25 times higher than the uncoated stainless steel or Ti-6Al-4V and about 5-10 times higher than all other nitrides. The technology may be applied to protect turbine engine compressor blades, vanes and rotor blades in advanced aircraft and fluid pump impellers as well as piston rings for heavy-duty diesel engines. (c) 2006 Elsevier B.V. All rights reserved. C1 SW Res Inst, San Antonio, TX 78238 USA. RP Wei, RH, SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78238 USA. EM rwei@swri.org CR DEMASIMARCIN JT, 1994, SURF COAT TECH, V68, P1 DISERENS M, 1998, SURF COAT TECH, V108, P241 FORTUNA SV, 2000, THIN SOLID FILMS, V377, P512 HAUERT R, 2000, ADV ENG MATER, V2, P247 HE JL, 1995, WEAR 1, V181, P189 HUO DH, 2001, THIN SOLID FILMS, V394, P72 HUO DH, 2001, THIN SOLID FILMS, V394, P81 HUO DH, 2002, THIN SOLID FILMS, V419, P11 MA D, 2006, THIN SOLID FILMS, V494, P438 MATOSSIAN J, 1998, SURF COAT TECH, V108, P496 MAYRHOFER PH, 2000, SURF COAT TECH, V133, P131 MUSIL J, 2000, SURF COAT TECH, V125, P322 REBOUTA L, 2000, SURF COAT TECH, V133, P234 RICKERBY DS, 1987, SURF COAT TECH, V33, P191 STACK MM, 2004, SURF COAT TECH, V188, P556, DOI 10.1016/j.surfcoat.2004.07.075 SUE JA, 1991, SURF COAT TECH, V49, P31 SWADZBA L, 1996, SURF COAT TECH, V78, P137 TABAKOFF W, 1989, SURF COAT TECH, V39, P97 VEPREK S, 1998, SURF COAT TECH, V108, P138 VEPREK S, 1998, THIN SOLID FILMS, V317, P449 VEPREK S, 2000, SURF COAT TECH, V133, P152 WEI RH, 2002, SURF COAT TECH, V158, P465 WHEELER DW, 2005, SURF COAT TECH, V199, P158 WOOD RJK, 1999, MATER DESIGN, V20, P179 YANG Q, 2004, SURF COAT TECH, V188, P168, DOI 10.1016/j.surfcoat.2004.08.012 ZHITOMIRSKY VN, 2000, SURF COAT TECH, V133, P114 NR 26 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 20 PY 2006 VL 201 IS 7 BP 4453 EP 4459 PG 7 SC Materials Science, Coatings & Films; Physics, Applied GA 121HW UT ISI:000243149700116 ER PT J AU Schonborn, A Chantzidakis, M AF Schonborn, Alessandro Chantzidakis, Matthew TI Development of a hydraulic control mechanism for cyclic pitch marine current turbines SO RENEWABLE ENERGY LA English DT Article DE cyclic; pitch; marine; tidal; current; turbine AB Tidal power generation by means of marine current farms is potentially a large renewable energy resource which could be harnessed in many coastal waters. Its availability is highly predictable in time, and the technology promises high energy conversion efficiency along with a relatively low impact on sea life due to its relatively small disturbance of natural tidal flows. A series of devices have so far been proposed and developed for the extraction and conversion of kinetic energy present in tidal flows into useful electrical power [1]. Designs include horizontal axis turbines, vertical axis turbines, and devices with oscillating lift surfaces. Up to date no technology has firmly established itself. This paper describes a novel hydraulic control mechanism designed for vertical-axis marine current turbines of the straight-bladed Darrieus type. It has been found to significantly improve turbine efficiency over conventional Darrieus turbines when operated at low blade tip-speed to tidal-flow-velocity ratios (TSR) and to give the turbine the ability to self-start reliably. The control mechanism enforces a cyclic pivoting motion on the turbine blades as they move around their circular flight-path. The movement of the pitch control is of sinusoidal shape and is continuously variable in amplitude. The blade actuation is powered by the turbine's own rotation and is implemented using a swash-plate mechanism in conjunction with a hydraulic circuit for every blade. For surface piercing turbines, this control mechanism may be remotely positioned in a dry nacelle above sea level. If the appropriate design is applied, this can offer access to the cyclic pitch control mechanism, gearbox and generator, even when the turbine is operational, promising lower maintenance and operating costs compared with submerged systems. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Coll London, Dept Mech Engn, London, England. RP Chantzidakis, M, Univ Coll London, Dept Mech Engn, Mortimer St, London, England. CR 1995, JOU2CT931355 *EUR COMM DIR GEN, 1996, JOU2CT920355 EUR COM BLACKWELL BF, 1976, WIND TUNNEL PERFORMA FRAENKEL PL, 2002, P IMECHE A, V216 FURUKAWA A, 1993, T JAPAN SOC MECH E B, V36, P135 GLAUERT H, 1948, ELEMENTS AEROFOIL AI JACOBS EA, 1935, 586 NAT ADV COMM AER MASSEY BS, MECH FLUIDS ROGERS GFC, THERMODYNAMIC TRANSP STRICKLAND JH, 1975, DARRIEUS TURBINE PER NR 10 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-1481 J9 RENEWABLE ENERGY JI Renew. Energy PD APR PY 2007 VL 32 IS 4 BP 662 EP 679 PG 18 SC Energy & Fuels GA 119BA UT ISI:000242986000009 ER PT J AU Almeida, DS Silva, CRM Nono, MCA Cairo, CAA AF Almeida, D. S. Silva, C. R. M. Nono, M. C. A. Cairo, C. A. A. TI Thermal conductivity investigation of zirconia co-doped with yttria and niobia EB-PVD TBCs SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE EB-PVD; TBC; ZrO2-Y2O3; ZrO2-Y2O3-Nb2O5; thermal conductivity ID BARRIER COATINGS; VAPOR-DEPOSITION; TETRAGONAL ZRO2; PHASE-STABILITY; TECHNOLOGY AB A technique used to improve the life cycle and/or the working temperature of the turbine blades uses ceramic coatings over metallic material applied by electron beam-physical vapor deposition (EB-PVD). The most usual material for this application is yttria doped zirconia. Addition of niobia, as a co-dopant in the Y2O3-ZrO, system, can reduce thermal conductivity. The purpose of this work is to evaluate the influence of the addition of niobia on the microstructure and thermal properties of the ceramic coatings. This new formulation will, in the future, be able to become an alternative to the composition currently used by the aerospace field in EB-PVD thermal barrier coatings (TBC). A significant reduction of the thermal conductivity, measured by laser flash technique, in the zirconia ceramic coatings co-doped with yttria and niobia when compared with zirconia-yttria coatings was observed. (c) 2006 Elsevier B.V. All rights reserved. C1 Comando Geral Tecnol Aerosp, Div Mat AMR CTA, BR-12228904 Sao Jose Dos Campos, SP, Brazil. Inst Nacl Pesquisas Espaciais, Lab Assoc Mat & Sensores, BR-12227010 Sao Jose Dos Campos, SP, Brazil. RP Almeida, DS, Comando Geral Tecnol Aerosp, Div Mat AMR CTA, Pca Marechal Ar Eduardo Gomes,50 Cep, BR-12228904 Sao Jose Dos Campos, SP, Brazil. EM dsa62@yahoo.com CR ALMEIDA DS, 2005, MATER SCI FORUM, V498, P453 ALMEIDA DS, 2006, SURF COAT TECH, V200, P2827, DOI 10.1016/j.surfcoat.2005.04.051 BEDDOES J, 1999, INTRO STAINLESS STEE, P315 COUTO P, 2003, METROLOGIA 2003 CZEK N, 1999, SURF COAT TECH, V113, P157 DEGIOVANNI A, 1986, REV PHYS APPL, V21, P229 EVANS AG, 2001, PROG MATER SCI, V46, P249 FUNATANI K, 2000, SURF COAT TECH, V133, P264 GOWARD GW, 1998, SURF COAT TECH, V108, P73 GUO HB, 2001, SCRIPTA MATER, V44, P683 GUO X, 1998, J EUR CERAM SOC, V18, P237 HASS DD, 2001, ACTA MATER, V49, P973 HASS DD, 2001, THESIS U VIRGINIA KIM DJ, 1990, J AM CERAM SOC, V73, P115 KIM DJ, 1991, J AM CERAM SOC, V74, P3061 LEE DY, 1998, J MATER SCI LETT, V17, P185 LIMA M, 2004, CERTIFICADO ANAL SER NICHOLLS JR, 1999, WEAR, V233, P352 NICHOLLS JR, 2002, SURF COAT TECH, V151, P383 RAGHAVAN S, 1998, SCRIPTA MATER, V39, P1119 RAGHAVAN S, 2001, ACTA MATER, V49, P169 SCHULZ U, 2000, SURF COAT TECH, V133, P40 SCHULZ U, 2003, AEROSP SCI TECHNOL, V7, P73 VYAS JD, 2000, MAT SCI ENG A-STRUCT, V277, P206 XU HB, 1998, THIN SOLID FILMS, V334, P98 ZHU D, NASATM200021038 NR 26 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 15 PY 2007 VL 443 IS 1-2 BP 60 EP 65 PG 6 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 117VK UT ISI:000242901200008 ER PT J AU Patterson, E Brailly, P Taroni, M AF Patterson, E. Brailly, P. Taroni, M. TI High frequency quantitative photoelasticity applied to jet engine components SO EXPERIMENTAL MECHANICS LA English DT Article DE quantitative photoelasticity; jet engine components; phase-stepping ID AUTOMATED PHOTOELASTICITY; STRESS-ANALYSIS; FRINGE AB For sometime, reflection photoelasticity has been used in a qualitative manner as an aid to the placement of strain gauges in vibration tests on turbine and compressor blades. Often, the motivation for such tests is the validation of numerical models used in life-time predictions. Strain gauges supply data at a small number of discrete points, whereas the photoelastic fringe patterns provide information over the whole field of view. Digital photoelasticity based on phase-shifting allows these fringe patterns to be processed into maps of surface strain data that can be used to verify the computational results. Digital photoelasticity has been developed over the last two decades utilising spectral or phase approaches sometimes combined with Fourier analysis; and in most reported applications only idealised case studies are considered. Recently, the application of digital photoelasticity in high frequency blade tests has been developed as a robust methodology that can be applied using standard equipment or using solid-state polariscopes. The paper includes descriptions of the methodology and exemplar results to demonstrate the efficacy of this advanced application of photoelasticity for full-field validations of numerical modelling. C1 Michigan State Univ, Dept Mech Engn, E Lansing, MI 48824 USA. SNECMA Moteurs, Ctr Villaroche, F-77556 Moissy Cramayel, France. RP Patterson, E, Michigan State Univ, Dept Mech Engn, 2555 Engn Bldg, E Lansing, MI 48824 USA. EM eann@egr.msu.edu CR *TN, 1977, TN701 *TN, 1978, TN704 AJOLAVISIT A, 1998, J STRAIN ANAL, V33, P75 AJOVALASIT A, 1995, EXP MECH, V35, P193 BARONE S, 1989, J STRAIN ANAL, V33, P223 BARONE S, 1996, EXP MECH, V36, P318 BHAT GK, 1999, P SEM SPRING C THEOR, P541 CARAZOALVAREZ J, 1994, OPT LASER ENG, V21, P133 ESTRADA JRE, 2004, EXP MECH, V44, P567, DOI 10.1177/0014485104049395 HAAKE SJ, 1993, INT C PHOT NEW INSTR JI W, 1998, EXP MECH, V38, P132 LESNIAK JR, 1998, P SEM SPRING C EXP A, P298 MORIMOTO Y, 1993, P SEM SPRING C EXP M, P1149 ORTIZ MH, 2005, EXP MECH, V45, P197 PATTERSON EA, 1988, STRAIN, V24, P15 PATTERSON EA, 1991, STRAIN, V27, P49 PATTERSON EA, 1998, J STRAIN ANAL ENG, V33, P1 PATTERSON EA, 2002, STRAIN, V38, P27 QUAN C, 1993, OPT LASER ENG, V18, P79 RAMESH K, 1996, J STRAIN ANAL ENG, V31, P423 RAMESH K, 2000, DIGITAL PHOTOELASTIC REDNER AS, 1984, P 5 INT C EXPT MECH, P421 SANFORD RJ, 1985, P SPRING C EXP MECH, P160 TARONI M, 2000, DISC P INT C EXPTL M WANG ZF, 1995, OPT LASER ENG, V22, P91 ZANDMAN F, 1977, SESA MONOGRAPHS, V3 NR 26 TC 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD DEC PY 2006 VL 46 IS 6 BP 661 EP 668 PG 8 SC Mechanics GA 119SY UT ISI:000243034800001 ER PT J AU Duo, P Liu, J Dini, D Golshan, M Korsunsky, AM AF Duo, P. Liu, J. Dini, D. Golshan, M. Korsunsky, A. M. TI Evaluation and analysis of residual stresses due to foreign object damage SO MECHANICS OF MATERIALS LA English DT Article DE residual stresses; foreign object damage; FOD; Ti6Al4V; high strain rate impact ID STATION 16.3; DIFFRACTION; PREDICTION; SRS AB Foreign object damage (FOD) in gas turbine engines occurs due to the ingestion of small inorganic particles (small stones and sand particles). The damage caused to the blade leading edge may lead to premature crack initiation and ultimately blade failure due the action of time-varying tensile loads. The problem of evaluating the severity of FOD and the induced reduction of component life was investigated in the laboratory, by reproducing the damage conditions accurately and subjecting the impacted blade to fatigue loading simulating the service conditions. One particular aspect of post-FOD analysis focuses on the evaluation of residual stresses in the vicinity of the notch. Residual stresses play an important role in controlling the rate of crack initiation and propagation, and may be responsible for accelerated crack growth if they are tensile ahead of the incipient crack, or can cause retardation otherwise. The present study was aimed at experimental and numerical investigate the magnitude and spatial variation of residual stresses in this region. Experimentally, a gas gun was used to introduce the damage by firing a hardened steel cube "point first". Following impact the residual stresses were evaluated using two different experimental techniques involving X-ray diffraction: laboratory low energy monochromatic stress measurement, and high-energy white beam synchrotron stress measurement. The results are compared with the numerical model of the impact phenomenon that was constructed for a selected portion of the blade material, and from which the residual stress pattern following simulated impact was calculated using Bammann damage material model. Both sets of experimental measurements are critically compared with the numerical result, and the relationship between them is discussed. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Oxford, Dept Engn Sci, Oxford OX1 3PJ, England. CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. RP Duo, P, Rolls Royce Deutschland Ltd & Co KG, Compressor Stress Grp, EE-32,Eschenweg 11, D-15827 Blankenfelde, Germany. EM pierangelo.duo@rolls-royce.com CR *LSTC, 2004, LSDYNA US GUID BAMMANN DJ, 1987, ACTA MECH, V69, P97 BAMMANN DJ, 1993, STRUCTURAL CRAHSWORT BRUKER AXS, 2002, STRESSPLUS SOFTWARE COLLINS SP, 1999, J PHYS D APPL PHYS, V32, A81 CULLITY BD, 2001, ELEMENTS XRAY DIFFRA DUO P, 2003, P 8 HIGH CYCL FAT C DUO P, 2004, 8 INT LSDYNA US C DUO P, 2004, P 9 NAT TURB ENG HCF DUO P, 2005, PREDICTION EXPT VALI DUO P, 2005, THESIS U OXFORD ELHADDAD MH, 1979, ENG FRACT MECH, V11, P573 HUDAK J, 1999, P 4 NAT TURB ENG HIG KITAGAWA H, 1976, P ICM, V2, P627 KORSUNSKY AM, 2002, J SYNCHROTRON RADI 2, V9, P77 KORSUNSKY AM, 2004, INT C COMP ENGNG SCI KRONER E, 1958, Z PHYS, V151, P504 LARSON AC, 2000, 86748 LAUR MALL S, 2001, MECH MATER, V33, P679 NOBLE JP, 1999, J MECH PHYS SOLIDS, V47, P1187 NOWELL D, 2003, INT J FATIGUE, V25, P963, DOI 10.1016/S0142-1123(03)00160-9 PREVEY P, 2004, P 9 INT HCF C PREVEY PS, 1986, XRAY DIFFRACTION RES, V10, P380 TOBY BH, 2001, J APPL CRYSTALLOGR 2, V34, P210 TRANTER PH, 2003, P 8 HIGH CYCL FAT C NR 25 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD MAR PY 2007 VL 39 IS 3 BP 199 EP 211 PG 13 SC Materials Science, Multidisciplinary; Mechanics GA 115HC UT ISI:000242724400001 ER PT J AU Chen, LJ Liu, YH Xie, LY AF Chen, Lijie Liu, Yinghua Xie, Liyang TI Power-exponent function model for low-cycle fatigue life prediction and its applications - Part I: Models and validations SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE power-exponent function model; low-cycle fatigue; life prediction; creep-fatigue; SRP method; LDS method ID NICKEL-BASE SUPERALLOY; BEHAVIOR; CREEP; TEMPERATURE; BILINEARITY; GH4049 AB Based on power transformation method, this paper advances a power-exponent function model for low-cycle fatigue (LCF) life prediction and then introduces it to creep-fatigue life prediction methods - the strain range partitioning (SRP) method and the linear damage summation (LDS) method for comprehensive assessment of power-exponent function model. Power transformation exponents (p) are given for some typical materials. Through LCF and creep-fatigue life predictions for these materials, we illustrate the validity of power-exponent function model and its applications. The comparisons between different models show that the power-exponent function model has better performances for LCF life prediction. In nature, Manson-Coffin law is the first order Taylor expansion approximation of power-exponent function model in log-log scale coordinates, corresponding to p = 1. The enhancement of nonlinearity makes the power-exponent function model and its applications to creep-fatigue life prediction methods more precise than the corresponding unmodified methods, whereas these models still use linear parameter regression method and remain simple for engineering applications. An example of these models' applications to life prediction of turbine blades under creep-fatigue interaction is given in the accompanying paper. (c) 2006 Elsevier Ltd. All rights reserved. C1 Tsing Hua Univ, Sch Aerosp, Dept Engn Mech, Beijing 100084, Peoples R China. NE Univ, Sch Mech Engn & Automat, Shenyang 110004, Peoples R China. RP Liu, YH, Tsing Hua Univ, Sch Aerosp, Dept Engn Mech, Beijing 100084, Peoples R China. EM yhliu@mail.tsinghua.edu.cn CR *AER IND SCI TECHN, 1987, STRAIN FAT AN HDB *AMSS CAS I MATH P, 1974, COMM MATH STAT TABL *BEIJ I AER MAT, 1992, HDB LOW CYCL FAT BATES DM, 1988, NONLINEAR REGRESSION BOX GEP, 1964, J R STAT SOC B, V26, P211 CHEN LJ, 1998, INT J FATIGUE, V20, P543 CHEN LJ, 1999, INT J FATIGUE, V21, P791 CHEN LJ, 1999, THESIS CHINESE ACAD CHEN LJ, 2000, FATIGUE FRACT ENG M, V23, P509 CHEN LJ, 2005, THESIS NE U HE JR, 1983, ASME INT C ADV LIF P, P27 HOAGLIN DC, 1983, UNDERSTANDING ROBUST LAGNEBORG R, 1971, METALL T, V2, P1821 MANSON SS, 1971, S DES EL TEMP ENV AS, P12 MANSSON SS, 1971, X67838 NASA TM NETER J, 1983, APPL LINEAR REGRESSI PRASAD NE, 1994, SCRIPTA METALL MATER, V30, P1497 RADHAKRISHNAN VM, 1992, INT J FATIGUE, V14, P305 SANDERS TH, 1976, MET TRANS A-PHYS MET, V7, P1407 SANKARAN S, 2003, MAT SCI ENG A-STRUCT, V345, P328 XU GX, 1995, MANAGERIAL STAT YE DY, 2004, MAT SCI ENG A-STRUCT, V373, P54, DOI 10.1016/j.msea.2004.01.045 NR 22 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD JAN PY 2007 VL 29 IS 1 BP 1 EP 9 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 112FL UT ISI:000242511000001 ER PT J AU Chen, LJ Liu, YH Xie, LY AF Chen, Lijie Liu, Yinghua Xie, Liyang TI Power-exponent function model for low-cycle fatigue life prediction and its applications - Part II: Life prediction of turbine blades under creep-fatigue interaction SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE life prediction; turbine blades; creep-fatigue interaction; modified linear damage summation method; modified strain range partitioning method ID SUPERALLOY GH4049 AB This paper is concerned with the applications of the proposed models, namely the modified linear damage summation (MLDS) method and the modified strain range partitioning (MSRP) method described in Part I of the series papers, to life prediction of turbine blades under creep-fatigue interaction. To begin with, a detailed FEM analysis is conducted considering peak loading of thermal load, centrifugal force and airflow force to determine life assessment positions. Secondly, according to the blades rig testing load, a stress-strain response analysis is performed for pure low-cycle fatigue (LCF) and creep fatigue interaction, in which steady-state temperature field, plastic kinematic hardening and contact between the blade body and hoop segment are taken into consideration to achieve accordance with practical conditions. Finally, based on FEM simulation results, the life of turbine blades is predicted using the five different models for creep-fatigue loading. A minimum safe and conservative life of 1293 h is given by the MLDS method based on power-exponent function model. The predicted lives by the MLDS and MSRP methods show reasonable agreement with the rig testing life, which further illustrates the validity of power-exponent function model and its applications. (c) 2006 Elsevier Ltd. All rights reserved. C1 Tsing Hua Univ, Dept Mech Engn, Sch Aerosp, Beijing 100084, Peoples R China. NE Univ, Sch Mech Engn & Automat, Shenyang 110004, Peoples R China. RP Liu, YH, Tsing Hua Univ, Dept Mech Engn, Sch Aerosp, Beijing 100084, Peoples R China. EM yhliu@mail.tsinghua.edu.cn CR 2001, AEROENGINE DESIGN HD, V18 CHEN GC, 2004, PEDOSPHERE, V14, P9 CHEN LJ, 2000, FATIGUE FRACT ENG M, V23, P509 CHEN LJ, 2005, J NE U NATURAL SCI, V26, P673 CHEN PS, 1998, JT ASME IEEE POW GEN HESELHAUS A, 1995, 953041 AIAA HOU JF, 2002, ENG FAIL ANAL, V9, P201 KAO KH, 1997, AIAA J, V35, P1472 LEWIS BL, 1983, SAE TECH PAPER SER, P4496 LI H, 1994, 942933 AIAA NISHIHARA T, 1958, T JPN SOC MECH ENG, V24, P424 ONAMI M, 1959, J JPN SOC TEST MAT, V8, P199 SONDAK DL, 2000, J PROPUL POWER, V16, P1141 STUBBS T, 2004, INSIGHT, V46, P529 VISWANATHAN R, 1987, J ENG GAS TURB POWER, V109, P115 WANG ZG, 1999, MET MATER-KOREA, V5, P597 WEI DK, 2002, J AEROENGINE, V1, P33 ZHANG MN, 1991, COLLECTIONS AEROENGI ZHOU ZQ, 2003, COMPUT-AIDED CIV INF, V18, P379 ZHU BT, 1996, TURBINE TECHNOL, V38, P132 NR 20 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD JAN PY 2007 VL 29 IS 1 BP 10 EP 19 PG 10 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 112FL UT ISI:000242511000002 ER PT J AU Oakley, SY Nowell, D AF Oakley, S. Y. Nowell, D. TI Prediction of the combined high- and low-cycle fatigue performance of gas turbine blades after foreign object damage SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE combined cycle fatigue; foreign object damage; modelling ID CRACK-GROWTH; CONJOINT ACTION; TI-6AL-4V AB This paper addresses the problem of predicting residual fatigue life on aircraft engine blades after foreign object damage. An elastic predictive approach is described based on arrest of short cracks propagating from a notch, which is an idealisation of the damage. This approach is extended for the case of combined cycle loading, where the blade experiences a combination of centrifugal and vibrational loading. Experiments were performed using ballistic impact to damage Ti6Al4V 'blade-like' specimens which are then tested in fatigue using a novel combined cycle test. The predictions are compared to the experimental results and shown to give satisfactory agreement. A further development of the approach is then described which enables the incorporation of shaken-down residual stresses, caused by the impact and subsequent fatigue loading. Some sample results are shown for a constant residual stress distribution and compared to the experimental results. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Oxford, Dept Engn Sci, Oxford OX1 3PJ, England. RP Nowell, D, Univ Oxford, Dept Engn Sci, Parks Rd, Oxford OX1 3PJ, England. EM david.nowell@eng.ox.ac.uk CR BOYCE BL, 2003, MAT SCI ENG A-STRUCT, V349, P48 CHEN X, 2002, J MECH PHYS SOLIDS, V50, P2669 CORRAN R, 2002, INT C FAT STOCKH COWLES BA, 1996, INT J FRACTURE, V80, P147 ELHADDAD MH, 1979, ENG FRACT MECH, V11, P573 HAWKYARD M, 1996, FATIGUE FRACT ENG M, V19, P217 HUDAK SJ, 2002, FATIGUE KITAGAWA H, 1976, P 2 INT C MECH BEH M, P627 KLESNIL M, 1972, MATER SCI ENG, V9, P231 MURAKAMI Y, 1990, STRESS INTENSITY FAC NOWELL D, 2003, INT J FATIGUE, V25, P963, DOI 10.1016/S0142-1123(03)00160-9 NOWELL D, 2003, J STRAIN ANAL ENG, V38, P429 OAKLEY SY, 2004, THESIS U OXFORD PETERS JO, 2001, INT J FATIGUE S, V23, S413 POWELL BE, 1987, INT J FATIGUE, V9, P195 POWELL BE, 1997, INT J FATIGUE, V19, S167 RODER O, 1999, 4 NAT TURB ENG HIGH RUSCHAU JJ, 2001, INT J IMPACT ENG, V25, P233 SCHOFIELD J, 2004, P 9 NAT TURB ENG HCF NR 19 TC 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD JAN PY 2007 VL 29 IS 1 BP 69 EP 80 PG 12 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 112FL UT ISI:000242511000007 ER PT J AU Bendeich, P Alam, N Brandt, M Carr, D Short, K Blevins, R Curfs, C Kirstein, O Atkinson, G Holden, T Rogge, R AF Bendeich, P. Alam, N. Brandt, M. Carr, D. Short, K. Blevins, R. Curfs, C. Kirstein, O. Atkinson, G. Holden, T. Rogge, R. TI Residual stress measurements in laser clad repaired low pressure turbine blades for the power industry SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE low pressure turbine blade; laser cladding; post-weld heat treatment; residual stress; FEA AB Low pressure turbine blades in power stations suffer from leading edge erosion damage due to water impingement. In an effort to extend the life of these blades, repair of the eroded regions has been proposed using laser cladding with Stellite material. However, the addition of Stellite results in residual stresses being generated in the parent metal due to contraction during cooling and differences in thermal expansion between the two materials. In this work test coupons and laser clad blades were examined for residual stresses using both the L3 diffractometer at the NRU reactor, Chalk River, Canada and the TASS strain scanner at ANSTO's HWAR reactor, Lucas Heights, Australia. In addition XRD results were used to measure residual stresses on the surface of the blade to complement the neutron measurements. An FEA model of a simplified weld was used to explain some of the results. Crown Copyright (c) 2006 Published by Elsevier B.V. All rights reserved. C1 Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. CSIRO, Mfg Sci & Technol, Woodville, SA 5011, Australia. Swinburne Univ Technol, IRIS, Hawthorn, Vic 3122, Australia. No Stress Technol, Deep River, ON K0J 1P0, Canada. CNR, Neutron Program Mat Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. RP Bendeich, P, Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. EM pbx@ansto.gov.au CR *ABAQUS, 2003, ABAQUS THEORY MANUAL, V1 *ASTM A, 76895 ASTM FITZPATRICK ME, 2003, ANAL RESIDUAL STRESS ROTHMAN MF, 1989, ASM INT WU AP, 2000, J MATER PROCESS TECH, V101, P70 NR 5 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 10 PY 2006 VL 437 IS 1 SI Sp. Iss. SI BP 70 EP 74 PG 5 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 103PG UT ISI:000241898600012 ER PT J AU Haans, W Sant, T van Kuik, G van Bussel, G AF Haans, Wouter Sant, Tonio van Kuik, Gijs van Bussel, Gerard TI Stall in yawed flow conditions: A correlation of blade element momentum predictions with experiments SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB Yawed flow conditions introduce unsteady loads in a wind turbine that affect generated power quality and fatigue life. An unsteady phenomenon of special concern is dynamic stall, due to the significant load fluctuations associated with it. Although the assumptions underlying blade element momentum (BEM) models are totally inadequate in yawed flow conditions, these models, modified with engineering models, are still widely used in industry. It is therefore relevant to assess the capabilities of BEM models in predicting the location of dynamic stall on the blade for a rotor in yawed flow conditions. A rotor model is placed in an open jet wind tunnel and tested in yawed flow conditions. The locations of dynamic stall on the blade of a rotor model as a function of the blade position are observed. Two experimental techniques are used; tufts glued to the blade and hot-film anemometry in the near wake. The results from the two techniques are compared and possible causes for differences are identified. Furthermore, the rotor model in yaw is modeled with a simple BEM model, utilizing a Gormont dynamic stall model. The regions of dynamic stall on the blades predicted by the BEM model are compared with the experimental results. The BEM model seems capable of a crude prediction of the dynamic stall locations found for the rotor model in yawed flow conditions. C1 Delft Univ Technol, Fac Aerosp Engn, NL-2629 HS Delft, Netherlands. Univ Malta, Msida, Malta. RP Haans, W, Delft Univ Technol, Fac Aerosp Engn, Kluyverweg 1, NL-2629 HS Delft, Netherlands. CR BRUUN HH, 1995, HOT WIRE ANEMOMETRY BURTON T, 2001, WIND ENERGY HDB COLEMAN R, 1945, L126 NACA WR CORTEN G, 2001, THESIS UTRECHT U UTR GORMONT R, 1973, 7267 US TR GROSS D, 1969, 25 ANN FOR AM HEL SO HAANS W, 2005, 31 EUR ROT FOR FLOR LEISHMAN J, 2000, PRINCIPLES HELICOPTE LEISHMAN JG, 2002, WIND ENERGY, V5, P85 MUNDUATE X, 2000, 19 ASME WIND EN S 38, P168 SANT T, 2004, 2004 EUR WIND EN C E, P117 SCHEPERS JG, 1999, 1999 ASME WIND EN S, P164 SNEL H, 1998, WIND ENERGY, V1, P46 VERMEER L, 1999, P 1999 EUR WIND EN C, P168 VERMEER L, 2001, 20 ASME WIND EN S 39, P1 VERMEER LJ, 2003, PROG AEROSP SCI, V39, P467, DOI 10.1016/S0376-0421(03)00078-2 YANG WJ, 1989, HDB FLOW VISUALIZATI NR 17 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2006 VL 128 IS 4 BP 472 EP 480 PG 9 SC Energy & Fuels; Engineering, Mechanical GA 105SE UT ISI:000242051800007 ER PT J AU Saranyasoontorn, K Manuel, L AF Saranyasoontorn, Korn Manuel, Lance TI Design loads for wind turbines using the environmental contour method SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID RELIABILITY-BASED DESIGN; EXTREME LOADS; MODELS AB When interest is in establishing ultimate design loads for wind turbines such that a service life of say, 20 years is assured, alternative procedures are available. One class of methods works by employing statistical loads extrapolation techniques following development first of 10-minute load maxima distributions (conditional on inflow parameters such as mean wind speed and turbulence intensity). The parametric conditional load distributions require extensive turbine response simulations over the entire inflow parameter range. We will refer to this first class of methods as the "parametric method." An alternative method is based on traditional structural reliability concepts and isolates only a subset of interesting inflow parameter combinations that are easily first found by working backward from the target return period of interest. This so-called inverse reliability method can take on various forms depending on the number of variables that are modeled as random. An especially attractive form that separates inflow (environmental) variables from turbine load/response variables and further neglects variability in the load variables given inflow is referred to as the environmental contour (EC) method. We shall show that the EC method requires considerably smaller amounts of computation than the parametric method. We compare accuracy and efficiency of the two methods in 1- and 20-year design out-of-plane blade bending loads at the root of two 1.5 MW turbines. Simulation models for these two turbines with contrasting features, in that one is stall-regulated and the other pitch-regulated, are used here. Refinements to the EC method that account for the effects of the neglected response variability are proposed to improve the turbine design load estimates. C1 Univ Texas, Dept Civil Architectural & Environm Engn, Austin, TX 78712 USA. RP Saranyasoontorn, K, Univ Texas, Dept Civil Architectural & Environm Engn, Austin, TX 78712 USA. CR *IEC, 1999, 88614001 IECTC BUHL ML, 2002, NRELEL50029798 BUHL ML, 2003, SNWIND USERS GUIDE CHENG PW, 2003, WIND ENERGY, V6, P1, DOI 10.1002/we.80 EFRON B, 1993, INTRO BOOTSTRAP FITZWATER LM, 2001, ASME, V123, P364 FITZWATER LM, 2002, J SOL ENERG-T ASME, V124, P378, DOI 10.1115/1.1509768 FITZWATER LM, 2003, P ASME WIND EN S JAN, P244 LARSEN DC, 1999, RISOR1111 RIS NAT LA MADSEN HO, 1988, STRUCT SAF, V5, P35 MADSEN PH, 1999, P 1999 ASME WIND EN, P355 MALCOLM DJ, 2002, NRELTP50034593 GLOB MANUEL L, 2001, J SOL ENERG-T ASME, V123, P346 MORIARTY PJ, 2002, J SOL ENERG-T ASME, V124, P387, DOI 10.1115/1.1510137 MORIARTY PJ, 2004, NRELTP50034421 PEERINGA JM, 2003, ECNC03131 RONOLD KO, 1994, P 5 EUR WIND EN C OC RONOLD KO, 2000, ENG STRUCT, V22, P565 ROSENBLATT M, 1952, ANN MATH STAT, V23, P470 SARANYASOONTORN K, 2004, J WIND ENG IND AEROD, V92, P789, DOI 10.1016/j.jweia.2004.04.002 VEERS PS, 1997, P ASME WIND EN S, P160 WINTERSTEIN SR, 1993, P INT C STRUCT SAF R WINTERSTEIN SR, 1998, INT C OFFSH MECH ARC NR 23 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2006 VL 128 IS 4 BP 554 EP 561 PG 8 SC Energy & Fuels; Engineering, Mechanical GA 105SE UT ISI:000242051800015 ER PT S AU Hyun, JS Song, GW Lee, YS AF Hyun, Jung-Seob Song, Gee-Wook Lee, Young-Shin TI Thermo-mechanical fatigue of the nickel base superalloy IN738LC for gas turbine blades SO ADVANCED NONDESTRUCTIVE EVALUATION I, PTS 1 AND 2, PROCEEDINGS SE KEY ENGINEERING MATERIALS LA English DT Article DE thermo-mechanical fatigue; superalloy; lifetime prediction; damage mechanisms AB A more accurate life prediction for gas turbine blade takes into account the material behavior under the complex thermo-mechanical fatigue (TMF) cycles normally encountered in turbine operation. An experimental program has been carried out to address the thermo-mechanical fatigue life of the IN738LC nickel-base superalloy. High temperature out-of-phase and in-phase TMF experiments in strain control were performed on superalloy materials. Temperature interval of 450-850 degrees C was applied to thermo-mechanical fatigue tests. The stress-strain response and the life cycle of the material were measured during the test. The mechanisms of TMF damage is discussed based on the microstructural evolution during TMF. The plastic strain energy based life pediction models were applied to the stress-strain history effect on the thermo-mechanical fatigue lives. C1 Korea Elect Power Res Inst, Power Generat Res Lab, Taejon, South Korea. Chungnam Natl Univ, Dept Mech Engn, Taejon 305764, South Korea. RP Hyun, JS, Korea Elect Power Res Inst, Power Generat Res Lab, 103-16 Munji Dong, Taejon, South Korea. EM jshyun@kepri.re.kr gwsong@kepri.re.kr yslee@shell.chungnam.ac.kr CR BERNSTEIN HL, 1993, ASTM STP, V1186, P212 FLEURY E, 1999, P KSME, A, P925 KARAYAKA M, 1991, METALL TRANS A, V22, P697 MORROW JD, 1965, ASTM STP, V378, P45 NEU RW, 1989, METALL TRANS A, V20, P1755 NITTA A, 1983, P ASME INT C ADV LIF, P131 REMY L, 1992, HIGH TEMPERATURE STR, P283 NR 7 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2006 VL 321-323 BP 509 EP 512 PG 4 SC Materials Science, Ceramics; Materials Science, Composites GA BFE19 UT ISI:000241427900112 ER PT J AU Prevey, PS Ravindranath, RA Shepard, M Gabb, T AF Prevey, Paul S. Ravindranath, Ravi A. Shepard, Michael Gabb, Timothy TI Case studies of fatigue life improvement using low plasticity burnishing in gas turbine engine applications SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID MECHANICAL SURFACE TREATMENTS; STEEL; DEFORMATION; STRENGTH; MICROSTRUCTURES; RESISTANCE; ALLOY; PARTS AB Surface enhancement technologies such as shot peening, laser shock peening, and low plasticity burnishing (LPB) can provide substantial fatigue life improvement. However to be effective, the compressive residual stresses that increase fatigue strength must be retained in service. For successful integration into turbine design, the process must be affordable and compatible with the manufacturing environment. LPB provides thermally stable compression of comparable magnitude and even greater depth than other methods, and can be performed in conventional machine shop environments on CNC machine tools. LPB provides a means to extend the fatigue lives of both new and legacy aircraft engines and ground-based turbines. Improving fatigue performance by introducing deep stable layers of compressive residual stress avoids the generally cost prohibitive alternative of modifying either material or design. The x-ray diffraction based background studies of thermal and mechanical stability of surface enhancement techniques are briefly reviewed, demonstrating the importance of minimizing cold work. The LPB process, tooling, and control systems are described. An overview of current research programs conducted for engine OEMs and the military to apply LPB to a variety of engine and aging aircraft components are presented. Fatigue performance and residual stress data developed to date for several case studies are presented including the following. (1) The effect of LPB on the fatigue performance of the nickel based super alloy IN718, showing the fatigue benefit of thermal stability at engine temperatures. (2) An order of magnitude improvement in damage tolerance of LPB processed Ti-6-4 fan blade leading edges. (3) Elimination of the fretting fatigue debit for Ti-6-4 with prior LPB. (4) Corrosion fatigue mitigation with LPB in Carpenter 450 steel. (5) Damage tolerance improvement in 17-4 PH steel. Where appropriate, the performance of LPB is compared to conventional shot peening after exposure to engine operating temperatures. C1 Lambda Res, Cincinnati, OH 45227 USA. NAVAIR, Patuxent River, MD 20670 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Prevey, PS, Lambda Res, 5521 Fair Lane, Cincinnati, OH 45227 USA. EM pprevey@lambda-research.com ravindranara@navair.navy.mil michael.Shepard@wpafb.af.mil timothy.gabb@lerc.nasa.gov CR 1998, 5826453, US 2002, 6415486, US 2002, NASA TECH BRIEFS AUG ALTENBERGER I, 1999, MAT SCI ENG A-STRUCT, V264, P1 BELKIN LM, 1983, SOVIET MAT SCI, V19, P225 BELKIN LM, 1984, SOV ENG RES, V4, P30 BELOZEROV VV, 1986, MET SCI HEAT TREAT, V28, P565 BRAHAM S, 1993, P COMP METH EXP MEAS, P255 CULLITY BD, 1978, ELEMENTS XRAY DIFFRA, P447 DRECHSLER A, 1998, MAT SCI ENG A-STRUCT, V243, P217 FATTOUH M, 1988, WEAR, V127, P123 FREID MK, 1994, PROT MET+, V20, P263 GABB T, 2002, ADV MATER PROCESS, P69 HILLEY ME, 1971, RESIDUAL STRESS MEAS HILLS DA, 1979, P INT C WEAR MAT ASM, P396 HOGAN B, 2001, MANUFACTURING ENG, P34 KOISTINEN DP, 1964, T ASM, V67, P67 KOTIVEERACHARI B, 1985, INT J PROD RES, V23, P499 LOH NH, 1989, WEAR, V129, P235 LOH NH, 1993, PRECIS ENG, V15, P100 MOORE MG, 1958, SAE T, V66, P340 NOYAN IC, 1987, RESIDUAL STRESS MEAS PAPSHEV DD, 1972, RUSS ENG J, V52, P48 PREVEY P, 2000, P 20 ASM MAT SOL C S PREVEY P, 2000, P 5 NAT HCF C PREVEY P, 2001, P 6 NAT TURB ENG HCF PREVEY PS, 1977, ADV XRAY ANAL, V20, P345 PREVEY PS, 1986, ADV XRAY ANAL, V29, P103 PREVEY PS, 1986, METALS HDB, V10, P380 PREVEY PS, 1987, RESIDUAL STRESS DESI STEPURENKO VT, 1976, PROT MET+, V12, P386 ZINN W, 1999, J MATER ENG PERFORM, V8, P145 NR 32 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2006 VL 128 IS 4 BP 865 EP 872 PG 8 SC Engineering, Mechanical GA 091RI UT ISI:000241045600016 ER PT J AU Arakere, NK Knudsen, E Swanson, GR Duke, G Ham-Battista, G AF Arakere, Nagaraj K. Knudsen, Erik Swanson, Gregory R. Duke, Gregory Ham-Battista, Gilda TI Subsurface stress fields in face-centered-cubic single-crystal anisotropic contacts SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID FRETTING-FATIGUE; MECHANICS AB Single-crystal superalloy turbine blades used in high-pressure turbomachinery are subject to conditions of high temperature, triaxial steady and alternating stresses, fretting stresses in the blade attachment and damper contact locations, and exposure to high-pressure hydrogen. The blades are also subjected to extreme variations in temperature during start-up and shutdown transients. The most prevalent high-cycle fatigue (HCF) failure modes observed in these blades during operation include crystallographic crack initiation/propagation on octahedral planes and noncrystallographic initiation with crystallographic growth. Numerous cases of crack initiation and crack propagation at the blade. leading edge tip, blade attachment regions, and damper contact locations have been documented. Understanding crack initiation/propagation under mixed-mode loading conditions is critical for establishing a systematic procedure for evaluating HCF life of single-crystal turbine blades. This paper presents analytical and numerical techniques for evaluating two- and three-dimensional (3D) subsurface stress fields in anisotropic contacts. The subsurface stress results are required for evaluating contact fatigue life at damper contacts and dovetail attachment regions in single-crystal nickel-base superalloy turbine blades. An analytical procedure is presented for evaluating the subsurface stresses in the elastic half-space, based on the adaptation of a stress function method outlined by Lekhnitskii (1963, Theory of Elasticity of an Anisotropic Elastic Body, Holden-Day, Inc., San Francisco, pp. 1-40). Numerical results are presented for cylindrical and spherical anisotropic contacts, using finite element analysis. Effects of crystal orientation on stress response and fatigue life are examined. Obtaining accurate subsurface stress results for anisotropic single-crystal contact problems require extremely refined 3D finite element grids, especially in the edge of contact region. Obtaining resolved shear stresses on the principal slip planes also involves considerable postprocessing work. For these reasons, it is very advantageous to develop analytical solution schemes for subsurface stresses, whenever possible. C1 Univ Florida, Gainesville, FL 32611 USA. NASA, George C Marshall Space Flight Ctr, Struct Mech Grp, Huntsville, AL USA. JE Sverdrup, Huntsville, AL USA. ERC Inc, Huntsville, AL USA. RP Arakere, NK, Univ Florida, Gainesville, FL 32611 USA. EM nagaraj@ufl.edu greg.swanson@nasa.gov greg.duke@mstc.nasa.gov battista@msfc.nasa.gov CR ARAKERE NK, 2000, 01GT585 ASME ARAKERE NK, 2001, J TRIBOL-T ASME, V123, P413 ARAKERE NK, 2002, J ENG GAS TURB POWER, V124, P161 ATTIA MH, 1992, STANDARDIZATION FRET BEISHEIM JR, 2002, GT200230306 ASME COWLES BA, 1996, INT J FRACTURE, V80, P1 DELUCA D, 1995, FR23800 OFF NAV RES DELUCA DP, 2000, COMMUNICATION DOMBROMIRSKI J, 1990, STANDARDIZATION FRET, P60 FAN H, 1994, J APPL MECH-T ASME, V61, P250 GELL M, 1986, PROCESSING PROPERTIE, P41 GIANNAKOPOULOS AE, 1998, ACTA MATER, V46, P2955 GREEN AE, 1954, THEORETICAL ELASTICI HILLS DA, 1994, MECH FRETTING FATIGU HOEPPNER DW, 1990, MECH FRETTING FATIGU, P23 JOHNSON KL, 1985, CONTACT MECH, P84 KNUDSEN EC, 2003, THESIS U FLORIDA GAI LEKHNITSKII SG, 1963, THEORY ELASTICITY AN, P1 RUIZ C, 1984, EXP MECH, V24, P208 SIMS CT, 1987, SUPERALLOYS, V2, P1 STOUFFER D, 1996, INELASTIC DEFORMATIO, P387 STROH AN, 1958, PHILOS MAG, V3, P625 SWANSON G, 2000, NASATP2000210074 SZOLWINSKI MP, 1996, WEAR, V198, P93 TURNER JR, 1979, INT J SOLIDS STRUCT, V16, P409 VERSNYDER FL, 1960, T ASM, V52, P485 VINGSBO O, 1988, WEAR, V126, P131 VLASSAK JJ, 2003, J MECH PHYS SOLIDS, V51, P1701, DOI 10.1016/S0022-5096(03)00066-8 WILLIS JR, 1966, J MECHANICS PHYSICS, V14, P163 NR 29 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2006 VL 128 IS 4 BP 879 EP 888 PG 10 SC Engineering, Mechanical GA 091RI UT ISI:000241045600018 ER PT J AU Marahleh, G Kheder, ARI Hamad, HF AF Marahleh, G. Kheder, A. R. I. Hamad, H. F. TI Creep life prediction of service-exposed turbine blades SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE stress-rupture test; Ni-based superalloy (IN 738); Larson-Miller parameter; life fraction rule AB The aim of this research work was to study the possibility of predicting the operational creep life of service-exposed blades used in industrial gas turbines. This prediction is based on the determination of blades creep life using stress-rupture test under accelerated test conditions where the applied stresses were 400,500 and 600 MPa and the test temperature was 850 degrees C. The study concentrated on creep behavior of service-exposed blades having different actual service lifes. The test specimens were prepared from first stage turbine blades made of Ni-based superalloy (IN-738). Larson-Miller parameter was used to extrapolate the stress-rupture test results to the actual operating conditions of blades. The operational creep life and the residual life of service-exposed blades were determined employing the life fraction rule. (c) 2006 Published by Elsevier B.V. C1 Al Balqa Appl Univ, Fac Engn, Dept Mat & Met Engn, Al Salt, Jordan. RP Marahleh, G, Al Balqa Appl Univ, Fac Engn, Dept Mat & Met Engn, Al Salt, Jordan. EM g_marahle@yahoo.com CR 1969, METHODS CREEP RUPTUR BARBOSA C, 2003, ACTA MACROSCOPICA SC, V12, P227 CASTILLO R, 1986, P C HIGH TEMP ALL GA, P1395 CASTILLO R, 1986, P C NICK MET, V1, P261 CASTILLO R, 1987, J ENG GAS TURB POWER, V109, P99 HART RV, 1976, J MET TECHNOL JAN, P1 LARSON FR, 1952, T ASME, V74, P765 MEYERS MA, 1999, MECH BEHAV MAT ULRICH K, 2004, MAT RES, V17, P1 WALSER B, 1979, P C HEAT MASS TRANSF, P673 XU Y, 1999, MAT SCI ENG A-STRUCT, V260, P48 NR 11 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2006 VL 433 IS 1-2 BP 305 EP 309 PG 5 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 088OQ UT ISI:000240821400044 ER PT J AU Huang, TW Cheng, PW AF Huang, Tsung-Wei Cheng, Po-Wen TI Changes in nasal resistance and quality of life after endoscopic microdebrider-assisted inferior turbinoplasty in patients with perennial allergic rhinitis SO ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY LA English DT Article ID SUBMUCOUS TURBINECTOMY; TURBINATE REDUCTION; QUESTIONNAIRE; SURGERY; OBSTRUCTION; DIATHERMY AB Objective: To assess objective and subjective outcomes in patients with perennial allergic rhinitis who had undergone endoscopic microdebrider-assisted inferior turbinoplasty. Design: Prospective study. Setting: Tertiary referral center. Patients: Fifty patients with perennial allergic rhinitis who had substantial mucosal hypertrophy of the inferior turbinates and who underwent endoscopic microdebrider-assisted inferior turbinoplasty with follow-up 1 year after surgery. Intervention: A newly designed microdebrider blade incorporated with an elevator was used to perform this procedure in the clinical setting with the patient under local anesthesia and with 30 endoscopic guidance. Main Outcome Measures: Both objective outcome evaluated by total nasal resistance at anterior rhinomanometry and subjective outcome assessed with the Rhinoconjunctivitis Quality of Life Questionnaire were analyzed before and 1 year after surgery. Results: The median total nasal resistance in 50 patients decreased from 0.45 Pa/cm(3) per second preoperatively to 0.28 Pa/cm(3) per second 1 year postoperatively, a statistically significant difference ( P <. 001). Compared with preoperative scores, the postoperative scores of these patients significantly improved in both 7 separate domain scores and overall Rhinoconjunctivitis Quality of Life Questionnaire scores ( P <. 005). Conclusion: Our results suggest that endoscopic microdebrider-assisted inferior turbinoplasty is effective for decreasing nasal resistance and improving quality of life in patients with perennial allergic rhinitis who have substantial nasal congestion. C1 Far Eastern Mem Hosp, Dept Otolaryngol, Taipei 220, Taiwan. RP Cheng, PW, Far Eastern Mem Hosp, Dept Otolaryngol, 21 Sect 2,Nan Ya S Rd, Taipei 220, Taiwan. EM powenjapan@yahoo.com.tw CR BIELAMOWICZ S, 1999, LARYNGOSCOPE, V109, P1007 FRIEDMAN M, 1999, LARYNGOSCOPE, V109, P1834 GOODE RL, 1978, J OTOLARYNGOL, V7, P262 GUYATT GH, 1992, J CLIN EPIDEMIOL, V45, P1341 JUNIPER EF, 1994, J CLIN EPIDEMIOL, V47, P81 JUNIPER EF, 1996, J ALLERGY CLIN IMMUN, V98, P843 JUNIPER EF, 1999, J ALLERGY CLIN IMM 1, V104, P364 LIPPERT BM, 1997, ANN OTO RHINOL LARYN, V106, P1036 MARTINEZ SA, 1983, LARYNGOSCOPE, V93, P871 MCCAFFREY TV, 2001, HEAD NECK SURG OTOLA, P261 MOORE JRM, 1980, J LARYNGOL OTOL, V94, P1411 MORI S, 1999, CLIN EXP ALLERGY, V29, P1542 MORI S, 2002, LARYNGOSCOPE, V112, P865 SETLIFF RC, 1994, AM J RHINOL, V8, P275 TALAAT M, 1987, J LARYNGOL OTOL, V101, P452 UTLEY DS, 1999, LARYNGOSCOPE, V109, P683 NR 16 TC 1 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610-0946 USA SN 0886-4470 J9 ARCH OTOLAR-HEAD NECK SURGERY JI Arch. Otolaryngol. Head Neck Surg. PD SEP PY 2006 VL 132 IS 9 BP 990 EP 993 PG 4 SC Otorhinolaryngology; Surgery GA 085HA UT ISI:000240593500010 ER PT J AU Wang, DL Li, JB Jin, T Wei, Z Hu, ZQ Fu, LQ Liu, SF AF Wang Donglin Li Jiabao Jin Tao Wei Zheng Hu Zhuangqi Fu Liqun Liu Shifeng TI Fatigue-life improvement of K417 alloy by shot peening and recrystallization SO RARE METAL MATERIALS AND ENGINEERING LA Chinese DT Article DE K417 alloy; shot peening; recrystallization; fatigue life ID SURFACE; COPPER AB K417 Ni-base superalloy is extensively used as the material of turbine blade of aeroengine. The feasibility of improving K417 fatigue life by surface shot peening and recrystallization was studied. The result shows that the fatigue life under the condition of 650 degrees C atmosphere is effectively enhanced by surface shot peening and recrystallization. The fractographs of specimen are analyzed by SEM, and the mechanism of fatigue life improvement is discussed. C1 Chinese Acad Sci, Inst Met Sci, Shenyang 110016, Peoples R China. Shenyang Liming Aeroengine Grp Corp Ltd, Ctr Tech, Shenyang 110043, Peoples R China. Shenyang Occupat Tech Coll, Shenyang 110043, Peoples R China. RP Wang, DL, Chinese Acad Sci, Inst Met Sci, Shenyang 110016, Peoples R China. EM wdltx@163.com CR ALBRECHT J, 1999, MAT SCI ENG A-STRUCT, V263, P176 BASINSKI ZS, 1983, ACTA METALL, V31, P591 BOND SD, 1984, J MATER SCI, V19, P3867 BOYDLEE AD, 1999, INT J FATIGUE, V21, P393 BURGEL R, 2000, SUPERALLOYS 2000, P229 CHEN GX, 1993, ANALECTS CAST SUPERA, P188 COLLINS JA, 1981, FAILURE MAT MECHANIC DAHLEN M, 1980, ACTA METALL, V28, P41 FORSYTH PJE, 1963, ACTA METALL, V11, P706 HUANG QY, 2000, SUPER ALLOY JOHN JB, 1982, ULTRAFINE GRAIN META KRAMER IR, 1986, MATER SCI ENG, V80, P37 OBLAK JM, 1966, T AIME, V242, P1563 OKAZAKI M, 2000, SUPERALLOYS 2000, P505 PORTER A, 1981, J MATER SCI, V16, P707 THOMPSON N, 1956, PHILOS MAG, V1, P113 TURNBULL A, 1995, FATIGUE FRACT ENG M, V18, P1455 YANG Y, 1986, HIGH TEMPERATURE STR NR 18 TC 1 PU NORTHWEST INST NONFERROUS METAL RESEARCH PI SHAANXI PA C/O RARE METAL MATERIAL ENGINEERING PRESS, PO BOX 51, XIAN, SHAANXI 710016, PEOPLES R CHINA SN 1002-185X J9 RARE METAL MAT ENG JI Rare Metal Mat. Eng. PD AUG PY 2006 VL 35 IS 8 BP 1294 EP 1298 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 081DE UT ISI:000240296600029 ER PT J AU Kong, C Kim, T Han, D Sugiyama, Y AF Kong, Changduk Kim, Taekhyun Han, Donju Sugiyama, Yoshihiko TI Investigation of fatigue life for a medium scale composite wind turbine blade SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE composite wind turbine blade; fatigue life; S-N damage equation; Spera's empirical equations AB In order to satisfy fatigue requirements in designing a cost effective wind turbine, the wind turbine blade, which is an expensive key component of the wind turbine system, must achieve very long operating life of 20-30 years. In this study, the fatigue life of a medium scale (750 kW) horizontal axis wind turbine system (HAWIS), which has been developed by the present study, was estimated by using the well-known S-N damage equation, the load spectrum and Spera's empirical formulae in order to confirm more than 20 years operating life. A specific fatigue procedure was proposed with the following three steps. Firstly, from the sample load spectrum data during short period operation, the spectrum data were rearranged as layer numbers, wind speeds, cycles per layer, normalized maximum, minimum, cyclic and average loads, and stress ratios in time order, and then the rearranged data were recorded as cyclic loads per median cyclic load, cycles per layer, cumulative cycles, probability of exceeding, and types of cycles, such as Type I, II and III. Secondly, fatigue loads, such as flapwise and chordwise bending moments were calculated by Spera's empirical equations with various engineering data of the studying blade for probability of exceeding. Finally, the allowable fatigue strengths were determined from laboratory fatigue property data for the S-N curve of E-glass/epoxy obtained by Mandell, empirical coefficients derived by Goodman diagram with the modified stress ratio and the required design life. In prediction of the fatigue life, it was confirmed that the composite wind turbine blade satisfies the design criteria for the 20 years fatigue life because of sufficient safety margins from the fatigue requirement. (c) 2006 Elsevier Ltd. All rights reserved. C1 Chosun Univ, Dept Aerosp Engn, Kwangju 501759, South Korea. Sunaerosys Inc, Res Inst, Nam Myun, Chung Nam, South Korea. Ryukoku Univ, Dept Mech & Syst Engn, Fushimi Ku, Kyoto, Japan. RP Kong, C, Chosun Univ, Dept Aerosp Engn, 375 Seosuk Dong, Kwangju 501759, South Korea. EM cdgong@mail.chosun.ac.kr CR 1985, WIND POWER MONTHLY I 1992, EMRC NISAII USERS MA ACKERMANN T, 2000, RENEW SUST ENERG REV, V4, P315 BECHLY ME, 1997, COMPUT STRUCT, V63, P639 FINGER RW, 1985, P WIND 85 C, P52 KIM JS, 2000, RENEWABLE ENERGY DEV KONG C, 1999, J KSPE, V3, P40 KONG C, 2000, J KSPE, V4, P22 KONG C, 2000, J KSPE, V4, P29 KONG C, 2000, KSAS INT J, V1 KONG C, 2000, P 3 AS PAC C AER TEC, P376 KONG C, 2001, 13 ITN C COMP MAT MANDELL JF, 1992, SAND927005 MINER MA, 1945, J APPL MECH, V12, P159 PALMGREN A, 1924, Z VER DTSCH ING, V68, P339 SPERA DA, 1993, WINDPOWER 93, P282 SPERA DA, 1994, WIND TURBINE TECHNOL NR 17 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD OCT PY 2006 VL 28 IS 10 BP 1382 EP 1388 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 079NW UT ISI:000240184700035 ER PT J AU Marchal, N Flouriot, S Forest, S Remy, L AF Marchal, N. Flouriot, S. Forest, S. Remy, L. TI Crack-tip stress-strain fields in single crystal nickel-base superalloys at high temperature under cyclic loading SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article DE crack; single crystal; superalloy; creep-fatigue; stress-strain field; high temperature ID ELEVATED-TEMPERATURE; FATIGUE; LOCALIZATION; BEHAVIOR; MODEL; ORIENTATION; SPECIMENS; GROWTH; DAMAGE AB This work is related to life prediction of high-pressure single crystal turbine blades. Stress and strain fields are first analysed at the tip of a static crack subjected to creep-fatigue loading, assuming an elasto-viscoplastic single crystal behaviour model. Local ratchetting effects are observed, depending on the distance from the crack-tip. Creep-fatigue loadings are compared with pure fatigue and pure creep loadings. The significant differences are pointed out, especially stress relaxation and amount of plastic slip. These results will be useful for the development of a new life prediction tool, based on local approach to fracture. (c) 2005 Elsevier B.V. All rights reserved. C1 Ecole Natl Super Mines, UMR 7633, ARMINES, Ctr Mat,CNRS, F-91003 Evry, France. RP Forest, S, Ecole Natl Super Mines, UMR 7633, ARMINES, Ctr Mat,CNRS, BP 87, F-91003 Evry, France. EM samuel.forest@ensmp.fr CR BESSON J, 2004, LOCAL APPROACH FRACT, P428 BUSSO EP, 2000, J MECH PHYS SOLIDS, V48, P2333 CAILLETAUD G, 1987, THESIS ECOLE NATL SU CHABOCHE JL, 2001, FATIGUE FRACT ENG M, V24, P405 CHIERAGATTI R, 1991, MAT SCI ENG A-STRUCT, V141, P11 CUITINO AM, 1992, MODELLING SIMUL MATE, V1, P225 CUITINO AM, 1996, J MECH PHYS SOLIDS, V44, P863 DEFRESNE A, 1990, MAT SCI ENG A-STRUCT, V129, P55 FEDELICH B, 2002, INT J PLASTICITY, V18, P1 FLEURY E, 1991, THESIS ECOLE NATL SU FLEURY E, 1993, MAT SCI ENG A-STRUCT, V167, P23 FLOURIOT S, 2003, COMP MATER SCI, V26, P61 FLOURIOT S, 2003, INT J FRACTURE, V124, P43 FOREST S, 1996, IUTAM S MICR PLAST D, P51 FOREST S, 2001, SCRIPTA MATER, V44, P953 GALLERNEAU F, 1999, INT J DAMAGE MECH, V8, P405 HANRIOT F, 1991, HIGH TEMPERATURE CON, P139 HENDERSON MB, 1996, ACTA MATER, V44, P111 KOSTER A, 2002, ESIS PUBLICATION, V29, P203 LI SX, 1998, INT J MECH SCI, V40, P937 MERIC L, 1991, J ENG MATER-T ASME, V113, P162 NOUAILHAS D, 1991, INT C HIGH TEMP CONS NOUAILHAS D, 1993, ADV MULTIAXIAL FATIG, P244 RICE JR, 1987, MECH MATER, V6, P317 RICE JR, 1990, INT J FRACTURE, V42, P301 NR 25 TC 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMPUT MATER SCI JI Comput. Mater. Sci. PD AUG PY 2006 VL 37 IS 1-2 BP 42 EP 50 PG 9 SC Materials Science, Multidisciplinary GA 066JI UT ISI:000239225100009 ER PT J AU Herzog, R Warnken, N Steinbach, I Hallstedt, B Walter, C Muller, J Hajas, D Munstermann, E Schneider, JM Nickel, R Parkot, D Bobzin, K Lugscheider, E Bednarz, P Trunova, O Singheiser, L AF Herzog, R. Warnken, N. Steinbach, I. Hallstedt, B. Walter, C. Mueller, J. Hajas, D. Muenstermann, E. Schneider, J. M. Nickel, R. Parkot, D. Bobzin, K. Lugscheider, E. Bednarz, P. Trunova, O. Singheiser, L. TI Integrated approach for the development of advanced, coated gas turbine blades SO ADVANCED ENGINEERING MATERIALS LA English DT Article ID THERMAL BARRIER COATINGS; CHEMICAL-VAPOR-DEPOSITION; LIFE PREDICTION MODEL; SINGLE-CRYSTAL BLADES; ALPHA-ALUMINA; STRESS STATE; FIELD MODEL; SIMULATION; SOLIDIFICATION; SUPERALLOYS AB This paper describes a through-process modelling on a microstructural level of the production of a coated turbine blade, including its in-service properties and degradation, accompanied by the actual production and testing of a CMSX-4 single crystal turbine blade dummy. The following steps are dealt with by modelling and experiment: solidification of the blade alloy during casting, microstructural changes during homogenization and aging heat treatments, chemical vapour deposition of an Al2O3 diffusion barrier coating, physical vapour deposition (sputtering) of a (Ni,Co)CrAlY bond coat, atmospheric plasma spraying of an Y2O3 stabilized ZrO2 thermal barrier coating and microstructural changes and development of critical stresses at in-service conditions. This work forms a part of the Collaborative Research Centre 370 (SFB370) "Integrative materials modelling". C1 ACCESS eV, D-52072 Aachen, Germany. Rhein Westfal TH Aachen, Inst Oberflachentech, D-52074 Aachen, Germany. KFA Julich GmbH, Forschungszentrum, Inst Werkstoffe & Verfahren Energietech 2, D-52428 Julich, Germany. RP Herzog, R, ACCESS eV, Intzestr 5, D-52072 Aachen, Germany. CR *HEAT MOM LTD, 2001, PHOENICS CVD VER 3 4 AHRENS M, 2002, SURF COAT TECH, V161, P26 ANDERSSON JO, 2002, CALPHAD, V26, P273 BAHLAWANE N, 2004, J ELECTROCHEM SOC, V151, C182, DOI 10.1149/1.1644604 BEDNARZ P, 2005, ADV CERAM COAT CERAM BOUTWELL BA, 1997, SUPERALLOYS 718 625, P99 BUSSO EP, 2001, ACTA MATER, V49, P1529 CAMPBELL CE, 2002, ACTA MATER, V50, P775 CATOIRE L, 2002, J ELECTROCHEM SOC, V149, C261 CHANG GC, 1987, SURF COAT TECH, V30, P13 CHENG J, 1998, ACTA MATER, V46, P5839 COLOMBIER C, 1986, INT J REFRACT HARD M, V5, P82 CORONELL DG, 1998, THIN SOLID FILMS, V333, P77 DURANDCHARRE M, 1997, MICROSTRUCT SUPERALL ECHSLER H, 2003, THESIS RWTH AACHEN U ECHSLER H, 2005, IN PRESS J MAT SCI ERITT U, 2000, THESIS RWTH AACHEN U ERITT U, 2002, MATERIALWISS WERKST, V33, P45 EVANS AG, 2001, PROG MATER SCI, V46, P505 FREBORG AM, 1998, MAT SCI ENG A-STRUCT, V245, P182 GOLDSCHMIDT D, 1994, MATERIALWISS WERKST, V25, P311 GOLDSCHMIDT D, 1994, MATERIALWISS WERKST, V25, P373 GOTTSTEIN G, 2004, ADV ENG MATER, V6, P617, DOI 10.1002/adem.200400049 GRAFE U, 2000, SCRIPTA MATER, V42, P1179 HAFF PK, 1976, APPL PHYS LETT, V29, P549 HECKMANN S, 1950, THESIS RWTH AACHEN U HECKMANN S, 2002, MAT ADV POWER ENG 1, P561 HERZOG R, 2005, CREEP FRACT HIGH TEM KASHKO T, 2003, P 4 INT C PLASM PHYS, V2, P475 KASHKO T, 2004, P NATL AC SCI BEL SE, P69 KERKHOFF G, 1998, MAT ADV POWER ENG 19, P1669 KLEIJN CR, 1995, PHOENICS J, V8, P404 KNOTEK O, 2005, ADHESION ASPECTS THI, V2, P145 KULKARNI A, 2003, ACTA MATER, V51, P2457, DOI 10.1016/S1359-6454(03)00030-2 KUNDAS S, 2001, P 15 INT PLANS SEM, V3, P360 KUNDAS S, 2002, INT THERM SPRAY C 20, P765 KURZ W, 1998, FUNDAMENTALS SOLIDIF LUGSCHEIDER E, 2000, P NATL ACAD SCI BEL, P134 LUGSCHEIDER E, 2000, PATON WELD J, V12, P40 LUGSCHEIDER E, 2001, ITSC 2001 NEW SURF N, P751 LUGSCHEIDER E, 2002, INT THERM SPRAY C EX, P42 LUGSCHEIDER E, 2003, SURF COAT TECH, V174, P475, DOI 10.1016/S0257-8972(03)00331-1 LUGSCHEIDER E, 2004, INT THERM SPRAY C 20, P311 LUGSCHEIDER E, 2004, J PHYS IV, V120, P373, DOI 10.1051/jp4:2004120042 LUGSCHEIDER E, 2005, 2005 BUS IND S SOC M, P13 LUGSCHEIDER E, 2005, SURF COAT TECH, V200, P913, DOI 10.1016/j.surfcoat.2005.02.141 LUGSCHIEDER E, 2003, 2003 BUS IND S SOC M, P117 MA D, 2000, INT J CAST METAL RES, V13, P85 MAJERUS P, 2002, MAT ADV POWER ENG 1, P551 MAJERUS P, 2003, THESIS RWTH AACHEN U MALZBENDER J, 2003, J MATER RES, V18, P1374 MULLER J, 1999, SURF COAT TECH, V120, P16 MULLER J, 2003, CHEM VAPOR DESPOSITI, V16, P186 MULLER J, 2003, VACUUM, V71, P247, DOI 10.1016/S0042-207X(02)00746-7 MULLER J, 2004, THESIS RWTH AACHEN U NITODAS SF, 2002, J ELECTROCHEM SOC, V149, C130 PAPENFUSSJANZEN N, 2002, BUS IND S 2002 SOC O, P137 REYNOLDS GW, 1984, NUCL INSTRUM METH B, V2, P804 ROSLER J, 2001, ACTA MATER, V49, P3659 ROSLER J, 2004, ACTA MATER, V52, P4809, DOI 10.1016/j.actamat.2004.06.046 SAHM PR, 1983, GIESSEREI FORSCH, V35, P35 SAUNDERS N, 1998, CALPHAD CALCULATION SCHEIL E, 1942, Z METALLKD, V34, P70 SCHIERLING M, 1999, J PHYS 4, V9 SFAR K, 2002, MAT SCI ENG A-STRUCT, V333, P351 SIGMUND P, 1969, PHYS REV, V184, P383 SIMS CT, 1987, SUPERALLOYS, V2 STEINBACH I, 1996, PHYSICA D, V94, P135 STEINBRECH RW, 2003, T INDIAN CERAM SOC, V62, P192 TIADEN J, 1998, PHYSICA D, V115, P73 TRUNOVA E, 2004, 28 INT C ADV CER C B, P411 TRUNOVA E, 2006, THESIS RWTH AACHEN U VASSEN R, 2001, MAT SCI ENG A-STRUCT, V303, P100 WALTER C, 2005, MAT SCI ENG A-STRUCT, V397, P385, DOI 10.1016/j.msea.2005.02.056 WARNKEN N, 2003, MOD CAST WELD ADV SO, P21 WILKE CR, 1950, CHEM ENG PROG, V46, P95 ZIEGLER JF, SRIM 2003 SOFTWARE P NR 77 TC 0 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1438-1656 J9 ADV ENG MATER JI Adv. Eng. Mater. PD JUN PY 2006 VL 8 IS 6 BP 535 EP 562 PG 28 SC Materials Science, Multidisciplinary GA 061UJ UT ISI:000238898000013 ER PT J AU Sakuma, A Matsuura, T Suzuki, T Watanabe, O Fukuda, M TI Upgrading and life extension technologies for geothermal steam turbines SO JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING LA English DT Article DE power generation; geothermal steam turbine AB In some aging geothermal steam turbines, the increased steam consumption is found out due to time deterioration of the turbine parts, mainly caused by erosion, corrosion damages or deposits of impurities on the steam paths. Furthermore, the heavy damage due to stress corrosion cracking or corrosion fatigue damage, etc. are observed on rotors, blades and other parts and components. On the other hand, in other units, the turbine output capacity decreases according to aging decrease of geothermal well pressure, that is, inlet steam pressure of turbine. Under these circumstances, upgrading and life extension are required for reliability and performance on geothermal steam turbines, particularly the existing ones. And as the effective utilization of geothermal energy is important from the viewpoint of decreasing carbon dioxide on environment problem, these technologies can, needless to say, be applied to new geothermal projects as well as the existing ones. This paper describes development and application of advanced steam path design such as nozzle and blade for improving reliability and performance, and of advanced rotor design and material including overlay coating technology for improving reliability and extending life. And also it describes uprating of the, existing units in opposition to aged decreasing in the inlet steam pressure. C1 Toshiba Co Ltd, Tsurumi Ku, Yokohama, Kanagawa 2300045, Japan. RP Sakuma, A, Toshiba Co Ltd, Tsurumi Ku, 2-4 Suehiro Cho, Yokohama, Kanagawa 2300045, Japan. EM akira4.sakuma@toshiba.co.jp CR AKIBA M, 1986, 86JPGCPWR29 ASME, P1 KAWAGISHI H, 1992, 92JPGCPWR18 ASME, P69 KAWAI M, 1979, TOSHIBA REV, V34, P399 SAKUMA A, 1998, TOSHIBA REV, V53, P14 TANUMA T, 1995, 954PGCPWR28 ASME, P80 WATANABE O, 1988, INT S GEOTH EN, P1 NR 6 TC 0 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1340-8054 J9 JSME INT J SER B JI JSME Int. J. Ser. B-Fluids Therm. Eng. PD MAY PY 2006 VL 49 IS 2 BP 186 EP 191 PG 6 SC Thermodynamics; Engineering, Mechanical GA 059OE UT ISI:000238741300002 ER PT J AU Suzuki, T Matsuura, T Sakuma, A Kodama, H Takagi, K Curtis, A TI Recent upgrading and life extension technologies for existing steam turbines SO JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING LA English DT Article DE power generation; steam turbine AB Electricity generation utilities are increasingly looking for cost-effective solutions to maximise the value of aging steam turbine generator plant assets. To this end, retrofits of steam turbines after many years of operation have been carried out for the purpose of life extension of units, performance improvements, capacity up-rating, availability improvement, and improved environmental compliance. Major steam turbine manufacturers have continued to push forward the development of advanced technologies to satisfy demand from utilities by provided retrofit design that optimise the above criteria. This paper describes the advanced technologies adopted in the recent retrofits, including advanced steam path design and new last stage blades of improved efficiency, improved reliability, and of simplified or no maintenance. Retrofit case-studies of capacity up-rating and life extension are introduced to illustrate how these technologies have been applied and what has been the gain. C1 Toshiba Co Ltd, Yokohama, Kanagawa 2300045, Japan. RP Suzuki, T, Toshiba Co Ltd, 2-4 Suehiro Cho, Yokohama, Kanagawa 2300045, Japan. EM akira4.sakuma@toshiba.co.jp CR BRANDON DR, 2004, POWER ENG AUG, P58 KAWAGISHI H, 1991, ASME PAPER PWR, V13, P63 KURIYAMA R, 1991, THERMAL NUCL POW JUL, P870 SHU R, 2001, E CHINA ELECT PO JUL, P21 SUZUKI A, 1993, ICOPE 93 SEPT, P503 NR 5 TC 0 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1340-8054 J9 JSME INT J SER B JI JSME Int. J. Ser. B-Fluids Therm. Eng. PD MAY PY 2006 VL 49 IS 2 BP 198 EP 204 PG 7 SC Thermodynamics; Engineering, Mechanical GA 059OE UT ISI:000238741300004 ER PT J AU Brun, K Kurz, R Simmons, HR TI Aerodynamic instability and life-limiting effects of inlet and interstage water injection into gas turbines SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Gas turbine power enhancement technologies, such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection, are being employed by end users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Particularly, the effect of these add-on devices, off-design operating conditions, nonstandard fuels, and compressor degradation/fouling on the gas turbines axial compressor surge margin and aerodynamic stability is often overlooked. Nonetheless, compressor aerodynamic instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure; i.e., a careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses nonstandard fuels. This paper discusses a simplified method to evaluate the principal factors that affect the aerodynamic stability of a single-shaft gas turbine's axial compressor. As an example, the method is applied to a frame-type gas turbine and results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities, but that it can be a contributing factor if for other reasons the machine's surge margin is already slim. The approach, described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure. C1 SW Res Inst, Mech & Mat Engn Div, San Antonio, TX 78228 USA. Solar Turbines Inc, San Diego, CA 92123 USA. RP Brun, K, SW Res Inst, Mech & Mat Engn Div, PO Drawer 28510, San Antonio, TX 78228 USA. EM kbrun@swri.org kurz_rainer_x@solarturbines.com hsimmons@swri.org CR BAGNOLI M, 2004, GT200453042 ASME BEHNKEN RL, 1997, 96014 CDS CALTECH BEHNKEN RL, 1997, P 1997 AM CONTR C AL, V2, P987 BHARGAVA R, 2002, GT200230560 ASME BHARGAVA R, 2003, GT200338187 ASME BHARGAVA R, 2003, P INT C POW ENG 03 I CHAKER M, 2002, GT200230562 ASME CHAKER M, 2002, GT200230563 ASME EMMONS HW, 1955, T ASME, V79, P455 GREITZER EM, 1976, ASME, V98, P190 HARTEL C, 2003, GT200338117 ASME HILL PJ, 1963, AERONAUT Q, V14, P331 HORLOCK JH, 2001, 2001GT0343 ASME INGISTOV S, 2001, 2001GT407 ASME INGISTOV S, 2002, 200230656 ASME JOLLY S, 2003, GT200338209 ASME KLEINSCHMIDT RV, 1947, MECH ENG, V69, P115 KURZ R, 2000, ASME T, V123, P70 MOORE FK, 1986, ASME, V108, P231 UTAMURA M, 1999, JOINT POW GEN C, P34 WHITE AJ, 2003, GT200338237 ASME WILCOX EC, 1951, 1006 NACA ZHENG Q, 1997, 97GT158 ASME ZHENG Q, 2002, GT200230590 ASME ZHENG Q, 2003, T ASME, V125, P160 NR 25 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 2006 VL 128 IS 3 BP 617 EP 625 PG 9 SC Engineering, Mechanical GA 058OO UT ISI:000238674500017 ER PT J AU Li, XC Wang, T TI Simulation of film cooling enhancement with mist injection SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE film cooling; turbine-blade cooling; mist cooling ID HEAT-TRANSFER; JET AB Cooling of gas turbine hot-section components, such as combustor liners, combustor transition pieces, and turbine vanes (nozzles) and blades (buckets), is a critical task for improving the life and reliability of them. Conventional cooling techniques using air-film cooling, impingement jet cooling, and turbulators have significantly contributed to cooling enhancements in the past. However the increased net benefits that can be continuously harnessed by using these conventional cooling techniques seem to be incremental and are about to approach their limit. Therefore, new cooling techniques are essential for surpassing these current limits. This paper investigates the potential of film-cooling enhancement by injecting mist into the coolant. The computational results show that a small amount of injection (2% of the coolant flow rate) can enhance the adiabatic cooling effectiveness about 30-50%. The cooling enhancement takes place more strongly in the downstream region, where the single-phase film cooling becomes less powerful. Three different holes are used in this study including a two-dimensional (2D) slot, a round hole, and a fan-shaped diffusion hole. A comprehensive study is performed oil the effect of flue gas temperature, blowing angle, blowing ratio, mist injection rate, and droplet size on the cooling effectiveness with 2D cases. Analysis on droplet history (trajectory and size) is undertaken to interpret the mechanism of droplet dynamics. C1 Univ New Orleans, Energy Convers & Conservat Ctr, New Orleans, LA 70148 USA. RP Li, XC, Univ New Orleans, Energy Convers & Conservat Ctr, 2000 Lakeshore Dr, New Orleans, LA 70148 USA. EM xli8@uno.edu CR *FLUENT INC, 2003, FLUENT MAN VERS 6 1 BELL CM, 2000, ASME, V122, P224 BRITTINGHAM RA, 2002, ASME, V122, P133 CHAKER M, 2002, ASME P TURB EXP 2002, V4, P413 DITTMAR J, 2003, J TURBOMACH, V125, P57, DOI 10.1115/1.1515337 ERIKSEN VL, 1974, ASME, V96, P239 GOLDSTEIN RJ, 1974, INT J HEAT MASS TRAN, V17, P595 GUO T, 2000, ASME, V122, P360 GUO T, 2001, ASME, V122, P749 JIA R, 2003, P ASME SUMM HEAT TRA, P845 KUO KY, 1986, PRINCIPLES COMBUSTIO KWAK JS, 2003, ASME, V125, P494 LAUNDER BE, 1972, LECT MATH MODELS TUR LI X, 2001, J HEAT TRANS-T ASME, V123, P1086 LI X, 2003, INT J HEAT MASS TRAN, V46, P2279, DOI 10.1016/S0017-9310(02)00521-5 LI X, 2005, P ASME INT MECH ENG LI XC, 2003, J HEAT TRANS-T ASME, V125, P438, DOI 10.1115/1.1561813 NIRMALAN NV, 1998, J TURBOMACH, V120, P50 PETR V, 2003, EN ENV P INT C EN EN, V1, P489 RANZ WE, 1952, CHEM ENG PROG, V48, P141 RANZ WE, 1952, CHEM ENG PROGR, V48, P173 WANG T, 2000, EXP THERM FLUID SCI, V22, P1 WANG T, 2004, P ASME INT MECH ENG WOLFSHTEIN M, 1969, INT J HEAT MASS TRAN, V12, P301 NR 24 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANSFER JI J. Heat Transf.-Trans. ASME PD JUN PY 2006 VL 128 IS 6 BP 509 EP 519 PG 11 SC Thermodynamics; Engineering, Mechanical GA 055ZG UT ISI:000238489400001 ER PT J AU Morita, A Kagawa, H Sugawara, M Kondo, Y Kubo, S TI Evaluation of corrosion fatigue crack propagation life at low-pressure steam turbine rotor groove SO ENGINEERING FRACTURE MECHANICS LA English DT Article DE life prediction; finite element method; crack propagation; corrosion fatigue; turbine rotor; rotor groove; hot water; life consumption rate AB The corrosion fatigue crack propagation life of Christmas-tree type rotor groove with three hooks is studied. Each corner of the hook can be a candidate for crack initiation site therefore the condition where cracks initiate and propagate simultaneously at several hook corners must be considered. When a blade is inserted in the rotor groove, narrow gap is introduced unavoidably between the rotor groove and the blade root. The effect of this narrow gap on the crack behavior must also be considered. A procedure was presented to assess the crack initiation and propagation behavior under such a condition. Using the procedure, crack initiation and propagation behavior was evaluated for several gap conditions. It was revealed that the gap condition had little effect on the relation between crack depth at the third hook corner and life consumption ratio (ratio of loading cycle to final failure life). A corrosion fatigue test was performed using a rotor groove model specimen, and the results were compared with the evaluation results. (c) 2006 Elsevier Ltd. All rights reserved. C1 Kansai Elect Power Co Inc, Power Engn R&D Ctr, Amagasaki, Hyogo 6610974, Japan. Kansai Elect Power Co Inc, Fossil Power Div, Ctr Engn, Design Engn Grp,Kita Ku, Osaka 5306591, Japan. Kyushu Univ, Grad Sch Engn, Higashi Ku, Fukuoka 8128581, Japan. Osaka Univ, Grad Sch Engn, Suita, Osaka 5650871, Japan. RP Morita, A, Kansai Elect Power Co Inc, Power Engn R&D Ctr, 11-20 Nakoji 3 Chome, Amagasaki, Hyogo 6610974, Japan. EM morita.akira@d4.kepco.co.jp kagawa.hiroyuki@e4.kepco.co.jp sugawara.manabu@b4.kepco.co.jp ykondo@mech.kyushu-u.ac.jp kubo@mech.eng.osaka-u.ac.jp CR FUJIWARA T, 1995, P INT S PLANT AG LIF KONDO Y, 1997, ASTM STP, V1298 PARKS DM, 1977, COMPUT MECH APPL MEC, P12 NR 3 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACTURE MECH JI Eng. Fract. Mech. PD AUG PY 2006 VL 73 IS 12 BP 1615 EP 1628 PG 14 SC Mechanics GA 057MN UT ISI:000238600000002 ER PT J AU Hand, MM Robinson, MC Balas, MJ TI Wind turbine response to parameter variation of analytic inflow vortices SO WIND ENERGY LA English DT Article DE vortex; modelling; coherent turbulence; stable boundary layer ID LOW-LEVEL JET AB As larger wind turbines are placed on taller towers, rotors frequently operate in atmospheric conditions that support organized, coherent turbulent structures. It is hypothesized that these structures have a detrimental impact on the blade fatigue life experienced by the wind turbine. These structures are extremely difficult to identify with sophisticated anemometry such as ultrasonic anemometers. This study was performed to identify the vortex characteristics that contribute to high-amplitude cyclic blade loads, assuming that these vortices exist under certain atmospheric conditions. This study does not attempt to demonstrate the existence of these coherent turbulent structures. In order to ascertain the idealized worst-case scenario for vortical inflow structures impinging on a wind turbine rotor, we created a simple, analytic vortex model. The Rankine vortex model assumes that the vortex core undergoes solid body rotation to avoid a singularity at the vortex centre and is surrounded by a two-dimensional potential flow held. Using the wind turbine as a sensor and the FAST wind turbine dynamics code with limited degrees of freedom, we determined the aerodynamic loads imported to the wind turbine by the vortex structure. We varied the size, strength, rotational direction, plane of rotation, and location of the vortex over a wide range of operating parameters. We identified the vortex conformation with the most significant effect on the blade root bending moment cyclic amplitude. Vortices with radii on the scale of the rotor diameter or smaller caused blade root bending moment cyclic amplitudes that contribute to high damage density. The rotational orientation, clockwise or counter-clockwise, produces little difference in the bending moment response. Vortices in the XZ plane produce bending moment amplitudes significantly greater than vortices in the YZ plane. Published in 2005 by John Wiley & Sons, Ltd. C1 Natl Renewable Energy Lab, Natl Wind Technol Ctr, Golden, CO 80401 USA. Univ Wyoming, Laramie, WY 82071 USA. RP Hand, MM, Natl Renewable Energy Lab, Natl Wind Technol Ctr, 1617 Cole Blvd,MS 3811, Golden, CO 80401 USA. EM maureen_hand@nrel.gov CR *INT EL COMM, 1998, 614001 IEC BANTA RM, 2002, BOUND-LAY METEOROL, V105, P221 BLUMEN W, 2001, DYNAM ATMOS OCEANS, V34, P189 BONNER WD, 1968, MONTHLY WEATHER REVI, V96, P833 BUHL ML, 2003, NRELEL50029798 ELLIOT DL, 1987, DOECH100934 PAC NW L GLINOU G, 1996, JOU2CT930378 CTR REN HAND MM, 2003, NRELTR0035172 HOCK SM, 1987, SERITR2173276 KELLEY N, 2002, NRELCP5003917 KELLEY N, 2004, NRELTR50034593 KELLEY ND, 1994, NRELTR4426008 KELLEY ND, 1996, NRELTR44220164 KELLEY ND, 2000, WIND ENERGY, V3, P121 LAINO DJ, 2003, USERS GUIDE WIND TUR MALCOLM DJ, 2002, NRELSR50032495 SNOW AL, 1989, SERISTR2173405 STULL RB, 1988, INTRO BOUNDARY LAYER SUTHERLAND H, 2002, 40 AIAA AER SCI M EX, P427 SUTHERLAND HJ, 1999, SAND990089 SAND NAT SUTHERLAND HJ, 2003, 41 AIAA AER SCI M EX, P214 WILSON RE, 1996, NRELSR50023563 NR 22 TC 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1095-4244 J9 WIND ENERGY JI Wind Energy PD MAY-JUN PY 2006 VL 9 IS 3 BP 267 EP 280 PG 14 SC Energy & Fuels; Engineering, Mechanical GA 054LB UT ISI:000238377100006 ER PT J AU Cunha, FJ Dahmer, MT Chyu, MK TI Thermal-mechanical life prediction system for anisotropic turbine components SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB Modern gas turbine engines provide large amounts of thrust and withstand severe thermal-mechanical conditions during the load and mission operations characterized by cyclic transients and long dwell times. All these operational factors call be detrimental to the service life of turbine components and need careful consideration. Engine components subject to the harshest environments are turbine high-pressure vanes and rotating blades. There, re, it is necessary to develop a turbine component three-dimensional life prediction sYstem, which accounts./or mission transients. anisotropic inaterial properties, and multi-axial, thermal-mechanical, strain, and stress fields. This paper presents a complete lift prediction approach for either commercial missions or more complex military missions, which includes evaluation of component transient metal temperatures, resolved maximum shear stresses and strains, and subsequent component life capability for fatigue and creep damage. The procedure is based oil considering all of the time steps ill the mission profile by developing a series of extreme points that envelop every point ill the mission. Creep damage is factored into the component capability by debiting thermal mechanical accumulated cycles using the traditional Miners ride for accumulated fatigue and creep damage. Application of this methodology is illustrated to the design of the NASA Energy Efficient Engine (E-3) high pressure turbine blade with operational load shakedown leading to stress relaxation oil the external hot surfaces and potential state of overstress in the inner cold rib regions of the airfoil. C1 Pratt & Whitney, United Technol Corp, E Hartford, CT 06108 USA. Univ Pittsburgh, Dept Mech Engn, Pittsburgh, PA 15261 USA. RP Cunha, FJ, Pratt & Whitney, United Technol Corp, E Hartford, CT 06108 USA. EM frank.cunha@pw.utc.com mkchyu@engr.pitt.edu CR *SWANS AN SYST INC, ANSYS US MAN, V1 ARAKERE NJ, 2001GT0585 ASME ARVANITIS ST, 1986, 86GT242 ASME BURGREEN D, 1968, 68WAMET14 ASME DAME TL, 1985, THESIS U CINCINNATI DELUCA DP, 1995, FR23800 ONR GARAFALO F, 1965, FUNDAMENTALS CREEP C HEINE JE, 1988, ERDCTR894027 LARSON FR, 1952, T ASME, V74, P765 LEKHNITSKII SG, 1963, THEORY ELASTICITY AN MACLACHLAN DW, 2000, METALL MATER TRANS A, V31, P1401 MACLACHLAN DW, 2001, FATIGUE FRACT ENG M, V25, P385 MACLACHLAN DW, 2001, FATIGUE FRACT ENG M, V25, P399 MCKNIGHT RL, CR165268 NASA MORENO V, 1985, CR174844 NASA NAIK RA, 2004, J ENG GAS TURB POWER, V126, P391, DOI 10.1115/1.1690768 NISSLEY DM, 1992, CR189223 NASA OZISIK MN, 1980, HEAT CONDUCTION SCHEID F, 1988, THEORY PROBLEMS NUME SEETHARAMAN V, 2002, THICKNESS DEBIT PROP SHAMES IH, 1997, ELASTIC INELASTIC ST SOECHTING FO, 1985, AFWALTR862124 STOUFFER DC, 1980, INELASTIC DEFORMATIO THULIN RD, 1982, CR165608 NASA NR 24 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD APR PY 2006 VL 128 IS 2 BP 240 EP 250 PG 11 SC Engineering, Mechanical GA 041NP UT ISI:000237463200004 ER PT J AU Naeem, M TI Impacts of low-pressure (LP) compressor's deterioration upon an aero-engine's high-pressure (HP) turbine blade's life consumption SO AERONAUTICAL JOURNAL LA English DT Article ID PERFORMANCE DETERIORATION AB Some in-service deterioration in any mechanical device, such as an aero-engine, is inevitable. As a result of experiencing a deterioration of efficiency and/or mass flow, an aero-engine will automatically adjust to a different set of operating characteristics; thereby frequently resulting in changes of rpm and/or turbine entry temperature in order to provide the same thrust. Rises in the turbine entry-temperatures and the high-pressure turbine's rotational speed result in greater rates of creep and fatigue damage being incurred by the hot-end components and thereby higher engine's life cycle costs. Possessing a better knowledge of the effects of engine deterioration upon the aircraft's performance, as well as fuel and life usages, helps the users to take wiser management decisions and hence achieve improved engine utilisation. For a military aircraft, using a Computer performance simulation, the consequences of low-pressure (LP) compressor's deterioration upon an aero-engine high-pressure (HP) turbine blade's life-consumption have been predicted. CR *ESDU, 1995, 95006 ESDU INT, V2 ACKER GF, 1987, 88GT206 ASME BASQUIN OH, 1910, P AM SOC TEST MATER, V10, P625 COFFIN LF, 1954, T ASME, V76, P931 DEVEREUX B, 1994, INT GAS TURB AER ENG DIAKUNCHAK IS, 1992, J ENG GAS TURB POWER, V114, P161 DOWLING NE, 1972, J MATERIALS JMLSA, V7, P71 DOWNING SD, 1982, INT J FATIGUE, V4, P31 HAUB GL, 1990, 90GT107 ASME JAMES AG, 1968, ADV ENG, V4 LAKSHMINARASIMH.AN, 1994, J ENG GAS TURB POWER, V116, P46 MANSON SS, 1953, 2933 NACA TN MATSUISHI M, 1968, JAP SOC MECH ENG C M MAY RJ, 1981, AIAA811652 NAEEM M, 1998, APPL ENERG, V60, P185 NAEEM M, 1999, THESIS CRANFIELD U NAEEM M, 2000, INT J FATIGUE, V22, P147 NAEEM M, 2001, AERONAUT J, V105, P685 PENNY RK, 1990, 90GT125 ASME RASKE DT, 1969, ASTM SPEC TECH PUBL, V465, P1 RYCHLIK I, 1987, INT J FATIGUE, V9, P119 SALLEE GP, 1980, NASACR135448 SALLEE GP, 1986, NASACR134769 SARAVANAMUTTOO HIH, 1985, 85GT153 ASME STEVENSON JD, 1995, 12 INT S AIR BREATH WU FE, 1994, THESIS CRANFIELD U NR 26 TC 2 PU ROYAL AERONAUTICAL SOC PI LONDON PA 4 HAMILTON PL, LONDON W1J 7BQ, ENGLAND SN 0001-9240 J9 AERONAUT J JI Aeronaut. J. PD APR PY 2006 VL 110 IS 1106 BP 227 EP 238 PG 12 SC Engineering, Aerospace GA 042ZQ UT ISI:000237569500003 ER PT J AU Gorla, RSR TI Numerical investigation of unsteady flow in a low pressure turbine SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article DE turbomachinery; unsteady flow; Navier Stokes solution ID AEROELASTICITY AB An unsteady, three-dimensional Navier-Stokes solution in rotating frame formulation for turbomachinery applications has been described. Casting the governing equations in a rotating frame enables the freezing of grid motion and results in substantial savings in computer time. The algorithm is an implicit finite volume solver designed for general unsteady multiple blade row turbomachinery computations. The k - epsilon turbulence model was used to model turbulence. The results for the unsteady pressure coefficient distribution on the suction and pressure surfaces are shown. The flow was observed to be unsteady and the properties change substantially with time. Therefore an account of this unsteadiness of pressure and. temperature on the thermal stresses has a lot of impact on the life of the blade. The distribution of flow angles for stator and rotor at various times is shown. Results were obtained for the overall pressure ratio and overall efficiency versus mass flow. C1 Cleveland State Univ, Dept Mech Engn, Cleveland, OH 44115 USA. RP Gorla, RSR, Cleveland State Univ, Dept Mech Engn, Cleveland, OH 44115 USA. CR BARAKOS G, 2001, AERONAUT J, V105, P419 BREARD C, 2002, J ENG GAS TURB POWER, V124, P196 CAMPOBASSO MS, 2003, J PROPUL POWER, V19, P250 CHEN JP, 1993, AIAA930676 CHEN JP, 1998, 983292 AIAA ERDOS JI, 1977, AIAA J, V15, P1559 JANUS JM, 1989, AIAA890206 LEWIS JP, 1989, ASME, V111, P387 MCBEAN IW, 2000, P 9 INT S UNST AER A ORE JF, 2003, P ASME FEDSM03 4 ASM, P6 NR 10 TC 0 PU FREUND PUBLISHING HOUSE LTD PI TEL AVIV PA PO BOX 35010, TEL AVIV 61350, ISRAEL SN 0334-0082 J9 INT J TURBO JET ENGINES JI Int. J. Turbo. Jet-Engines PY 2006 VL 23 IS 1 BP 1 EP 13 PG 13 SC Engineering, Aerospace GA 037BH UT ISI:000237121200001 ER PT S AU Waki, H Nishikawa, I Ohmori, A TI Evaluation of adhesive strengths of plasma-sprayed CoNiCrAlY coatings using an indentation method SO FRACTURE AND STRENGTH OF SOLIDS VI, PTS 1 AND 2 SE KEY ENGINEERING MATERIALS LA English DT Article DE adhesive strength; delamination; plasma spray coating; CoNiCrAlY; thermal barrier coating; indentation method AB Thermal barrier coating (TBC) on the element for high temperature service, such as a gas turbine blade, has become an indispensable technology. In this study, adhesive strengths of plasma-sprayed CoNiCrAlY coatings were examined using an indentation method. In order to examine the effects of the spraying process on the adhesive strength of a sprayed coating, coatings were deposited by both atmospheric plasma spraying (APS) and low pressure plasma spraying (LPPS). The half number of CoNiCrAIY(LPPS) specimens were thermally aged for diffusion treatment. The load-displacement curves during the indentation were measured, and the delamination energy per unit area of delamination was estimated. The delamination load was high when the distance from an edge of a specimen was long, however the energy per unit delamination area was almost independent of the distance from the edge and was uniquely determined. The delamination. energy of CoNiCrAIY(APS) and CoNiCrAIY(LPPS) coatings were found to be approximately the same. The delamination energy of CoNiCrAlY(LPPS) with diffusion thermal treatment was widely scattered as compared with foregoing two coatings, however the energy of the CoNiCrAIY(LPPS) coating with diffusion thermal treatment was found to be about three times higher than those of both CoNiCrAIY(APS) and CoNiCrAlY(LPPS) coatings. It was concluded that diffusion thermal treatment was effective in improving the delamination strength. The CoNiCrAIY(LPPS) coating with diffusion thermal treatment was also found to be effective in improving the fatigue fracture life of a thermal-barrier-coated material. C1 Osaka Electrocommun Univ, Dept Mech Engn, Neyagawa, Osaka 5728530, Japan. Osaka Inst Technol, Dept Mech Engn, Asahi Ku, Osaka 5358585, Japan. Osaka Univ, Joining & Welding Res Inst, Ibaraki, Osaka 5670047, Japan. RP Waki, H, Osaka Electrocommun Univ, Dept Mech Engn, 18-8 Hatsu Cho, Neyagawa, Osaka 5728530, Japan. EM awaki@isc.osakac.ac.jp nishikawa@med.oit.ac.jp ohmori@jwri.osaka-u.ac.jp CR 1994, H8666 JIS LI CW, 2004, KEY ENG MAT 1&2, V261, P447 NAKASA K, 1998, J SOC MAT SCI JPN, V47, P413 WAKI H, P 12 MAT PROC C JSME, P268 WAKI H, 2004, MAT SCI ENG A-STRUCT, V374, P129, DOI 10.1016/j.msea.2004.02.040 NR 5 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2006 VL 306-308 PN Part 1-2 BP 387 EP 392 PG 6 SC Materials Science, Ceramics; Materials Science, Composites GA BEC99 UT ISI:000236852900065 ER PT J AU Conner, BP Nicholas, T TI Using a dovetail fixture to study fretting fatigue and fretting palliatives SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID ON-FLAT CONTACT; TI-6AL-4V; PLASTICITY AB Fretting fatigue damage can reduce the service life of engineering components in contact. The attachment between blades and disks in the fan and compressor stages of gas turbine engines is often a dovetail geometry. As a result, normal and tangential cyclic contact loads are present. Results of fretting fatigue tests using a new dovetail fixture are detailed here. Dovetail specimens and three types of contact pads were all machined out of Ti - 6A1 - 4V. Two types of palliatives are also examined: aluminum bronze coatings and low-plasticity, burnishing. While the palliatives were effective in increasing the fatigue life, the three pad geometries produced essentially the same fatigue life. C1 MIT, Cambridge, MA 02139 USA. Univ Dayton, Res Inst, Struct Integr Div, Dayton, OH 45469 USA. RP Conner, BP, MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM bpconner@alum.mit.edu CR *PRAX SURF TECHN, 1999, COAT DAT LCU 2 BEGLEY MR, 1999, ENG FRACT MECH, V62, P145 GALLAGHER JP, 2001, AFRLMLWPTR20014159 U GOLDEN PJ, 2005, FATIGUE FRACT ENG M, V28, P1169 HERTZ H, 1882, J REINE ANGEW MATH, V92, P156 HILLS DA, 1994, MECH FRETTING FATIGU HUTSON AL, 1999, INT J FATIGUE, V21, P663 HUTSON AL, 2000, AM SOC TEST MATER, V1367, P308 HUTSON AL, 2001, INT J FATIGUE S1, V23, P445 KIM AS, 1997, INT J SOLIDS STRUCT, V34, P3415 KIRKPATRICK GW, 1999, THESIS MIT CAMBRIDGE KOUL AK, 1996, 82 M AGARD STRUCT MA LINDLEY TC, 1992, STANDARDIZATION FRET, P153 MAXWELL DC, 1999, ASTM STP, V1321, P626 NICHOLAS T, 2003, INT J FATIGUE, V25, P1069, DOI 10.1016/S0142-1123(03)00115-4 PETERS JO, 2000, METALL MATER TRANS A, V31, P1571 RUIZ C, 1984, EXP MECH, V24, P208 RUIZ C, 1986, P INT C FAT SHEFF UK RUIZ C, 2000, ESIS PUBLICATION, V26, P73 STODOLA A, 1927, STEAM GAS TURBINES TADA H, 1973, STRESS ANAL CRACKS H WATERHOUSE RB, 1987, ADV SURFACE TREATMEN, V4, P517 WITTKOWSKY BU, 1999, FATIGUE FRACT ENG M, V22, P307 NR 23 TC 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-4289 J9 J ENG MATER TECHNOL JI J. Eng. Mater. Technol.-Trans. ASME PD APR PY 2006 VL 128 IS 2 BP 133 EP 141 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 028ZC UT ISI:000236526300002 ER PT J AU Ozgener, O TI A small wind turbine system (SWTS) application and its performance analysis SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE energy; environment; exergy; renewable energy; sustainable development; wind; wind energy ID LOCAL DESIGN; BLADES; ENERGY AB Energy conservation, pollution prevention, resource efficiency, systems integration and life cycle costing are very important terms for sustainable construction. The purpose of this work is to ensure a power supply for the north of the Solar Energy Institute building environment lamps by using wind power to comply with the green building approach. Beside this, the study is to present an energy analysis of the 1.5 kW small wind turbine system (SWTS) with a hub height of 12 m above ground level with a 3 in rotor diameter in Turkey. The SWTS was installed at the Solar Energy Institute of Ege University (latitude 38.24 N, longitude 27.50 E), Izmir, Turkey. NACA 63-622 profile type (National Advisory Committee for Aeronautics) blades of epoxy carbon fiber reinforced plastics were used. The system was commissioned in September 2002, and performance tests have been conducted since then. The performance analysis of the SWTS is quantified and illustrated in the tables, particularly for a reference temperature of 25 degrees C, 30th of October 2003 till 5th of November 2003 for comparison purposes. Test results show that when the average wind speed is 7.5 m/s, 616 W and 76 Hz electricity is produced by the alternator. (c) 2005 Elsevier Ltd. All rights reserved. C1 Ege Univ, Solar Energy Inst, TR-35100 Bornova, Izmir, Turkey. RP Ozgener, O, Ege Univ, Solar Energy Inst, TR-35100 Bornova, Izmir, Turkey. EM onder.ozgener@ege.edu.tr CR 2002, NRELSR50030117 ABBOTT IH, 1932, 451 NACA ABBOTT IH, 1945, 824 NACA ABBOTT IH, 1959, THEORY WING SECTIONS ACKERMANN T, 2002, RENEW SUST ENERG REV, V6, P67 CENGEL YA, 1994, THERMODYNAMICS ENG A CENGEL YA, 2001, FUNDAMENTALS THERMAL COLAK M, 1999, INVESTIGATION RELATI COTRELL J, 2002, 50026645 NRELTP DOOLING R, 2002, 50030844 NRELTP FINGERSH LJ, 2002, 50032879 NRELTP FUJISAWA N, 1987, WIND ENG, V11, P195 HABALI SM, 2000, ENERG CONVERS MANAGE, V41, P249 HABALI SM, 2000, ENERG CONVERS MANAGE, V41, P281 HAPEL KH, 1990, STABILITY ANAL DYNAM HAU W, 1996, WIND TURBINES HEPBASLI A, 2001, ENERG SOURCE, V23, P33 HEPBASLI A, 2004, RENEW SUST ENERG REV, V8, P257, DOI 10.1016/j.rser.2003.10.006 HOLMAN JP, 2001, EXPT METHODS ENG, P48 HOME B, 1994, WHERE WIND BLOWS KAW AK, 1997, MECH COMPOSITE MAT, P194 KERLINGER P, 2002, 50028591 NRELSR KOSEOGLU F, 2003, COMMUNICATION MALCOM DJ, 2002, 50032495 NRELSR MALLICK PK, 1997, COMPOSITES ENG HDB, P13 MCNIFF B, 2002, 50031115 NRELSR MOMENT R, 1984, SHORT SEMINAR PRESEN, P10 MONTGOMERIE B, 2000, IEA JOINT ACT AER WI, P113 MULJADI E, 2001, 50030412 NRELCP MULJADI E, 2002, 50030768 NRELCP OZGENER O, 2002, THESIS EGE U IZMIR T, P92 OZGENER O, 2003, 2001GEE004 EG U RES, P34 OZGENER O, 2004, ENERG SOURCE, V26, P891, DOI 10.1080/00908310490465948 OZGENER O, 2004, RENEW SUST ENERG REV, V9, P85 RASMUSSEN F, 2003, WIND ENERGY, V6, P213, DOI 10.1002/we.98 ROBINSON MC, 1996, RENEW ENERG, V10, P265 SADHY D, 1995, WIND ENG, V9 SMITH B, 2002, 50032494 NRELCP SNEL H, 1998, WIND ENERGY, P46 SNEL H, 2003, WIND ENERGY, V6, P203, DOI 10.1002/we.97 SOLENER MC, 2003, 15 KW VELTER XV WING SPERA DA, 1994, AM SOC MECH ENG, V430, P283 TANGLER J, 1990, ECWEC 90 TANGLER JL, 2002, 50031243 NRELCP TWIDELL J, 1987, BRIT WIND ENERGY ASS VANDAM J, 2002, 50031666 NRELTP WINDMILLS GH, 1963, AERODYNAMIC THEORY, V14, P324 WOOLLEY R, 1997, GREEN BUILDING HDB, V1 WRIGHT A, 2002, 50031164 NRELCP WRIXON GT, 2000, RENEWABLE ENERGY NR 50 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONV MANAGE JI Energy Conv. Manag. PD JUL PY 2006 VL 47 IS 11-12 BP 1326 EP 1337 PG 12 SC Thermodynamics; Energy & Fuels; Mechanics; Physics, Nuclear GA 028XN UT ISI:000236522200002 ER PT J AU Hamed, A Tabakoff, W Wenglarz, R TI Erosion and deposition in turbomachinery SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID PARTICLE RESTITUTION CHARACTERISTICS; PERFORMANCE DETERIORATION; REBOUND PARAMETERS; LASER MEASUREMENTS; BLADE EROSION; GAS-TURBINES; FLY-ASH; DYNAMICS; ENGINE; FLOW AB This paper presents a review of erosion and deposition research in turbomachines and the associated degradation in engine performance caused by particulate matter ingestion. Parameters affecting surface material losses as a result of erosion and development of experimental and analytical approaches to predict flowpath erosion and deposition are discussed. Tests results that quantify the effects of temperature, impact particle composition, impact velocity and angle, and surface material composition are reviewed along with particle restitution data (ratios of rebound to impact velocities and angles). Development and application of models using these data to calculate surface erosion in turbomachinery are described. These models predict particle trajectories in turbomachinery passages to determine impact rates, impact velocities, impact angles and uses the experimentally-obtained erosion data to calculate material losses. Literature on the effects of erosion on turbomachine performance and life is surveyed. Mechanisms of particle delivery and attachment upon arrival at turbomachine flowpath surfaces are also discussed along with experiential models that have been developed to predict surface deposit buildup. Delivery to turbine surfaces can occur as a result of inertial flight, as for erosion, but also through transport mechanisms involving turbulence, Brownian diffusion, and thermophoresis. The particle size range, where each of these mechanisms is dominant for delivery to surfaces, is described. The history and experience of developing models that use these mechanisms to quantify particle delivery rates to turbine flow path surfaces is discussed, along with the use of sticking fraction data to determine the amount of material retained on the surfaces after delivery and the resulting deposit buildup rates. Finally, factors that control whether extreme rates of deposition can occur in turbomachinery are described. C1 Univ Cincinnati, Cincinnati, OH 45221 USA. S Carolina Inst Energy Studies, Clemson, SC 29634 USA. RP Hamed, A, Univ Cincinnati, Cincinnati, OH 45221 USA. CR AHLUWALIA RK, 1986, 86GT239 ASME ATKIN ML, 1971, 133 AUSTR DEF SCI SE BALAN C, 1984, 841208 AIAA BATCHO PF, 1978, INTERPRETATION GAS T, V109, P344 BEACHER B, 1984, 84GT122 ASME BONS JP, 2001, 2001GT0163 ASME CHAMBERS JC, 1985, 850097 AIAA CLEAVER JW, 1975, CHEM ENG SCI, V30, P983 CLEVENGER W, 1976, J AIRCRAFT, V13, P786 DAVIES CN, 1966, AEROSOL SCI DOSANJH S, 1985, WEAR, V102, P309 DRING RP, 1979, J ENERGY, V3, P161 DUNN MG, 1987, J ENG GAS TURB POWER, V109, P336 DUNN MG, 1994, 94GT170 ASME DUSSOURD JL, 1983, 83GR164 ASME EDWARDS VR, 1994, AGARDCP558 ELBATSH H, 2000, 2000GT519 ASME ELBATSH H, 2002, GT200230600 ASME ELFEKI S, 1986, 86GT240 ASME FINNIE I, 1960, P SOC EXP STRESS, V17, P65 FINNIE I, 1960, WEAR, V3, P87 FRACKRELL J, 1994, 94GT467 ASME FRIEDLANDER SK, 1957, INDUSTRIAL ENGINEERI, V49, P1151 GHENAIET A, 2001, 2001GT0497 ASME GRANT G, 1975, J AIRCRAFT, V12, P471 HAMED A, 1992, J ENG GAS TURB POWER, V114, P235 HAMED A, 1994, EROSION CORROSION FO HAMED A, 1995, J ENG GAS TURB POWER, V117, P432 HAMED A, 1998, INT J ROTATING MACH, V4, P243 HAMED A, 2004, ASMEIGTI200454328 HIDY GM, 1978, RECENT DEV AEROSOL S, P135 HUSSEIN M, 1973, J AIRCRAFT, V10, P334 HUSSEIN MF, 1974, COMPUTER FLUIDS, V2, P1 HUTCHINGS WH, 1983, WEAR, V34, P269 KLEINERT G, 1990, SERMATECH REV, V33, P2 KLINE M, 2004, GT200454336 ASME KOTWAL R, 1981, J ENG POWER-T ASME, V103, P265 LIN CS, 1953, IND ENG CHEM, V45, P636 MACCAY R, 1969, 69GT20 ASME MANN DL, 1994, AGARDCP588 MCCREATH CG, 1982, POWER IND RES, V2, P1 MENGUTURK M, 1981, 81GT54 ASME METWALLY M, 1995, J ENG GAS TURB POWER, V117, P213 MITCHELL HJ, 1982, RDATR120012001 MOORE MJ, 1973, DEPOSITION CORROSION, P35 MUND MG, 1970, 70GT104 ASME NAGY DR, 1994, AGARDCP558 NAIK SK, 2004, GT200454330 ASME OKA YI, 2001, WEAR 1, V250, P736 PARKER GJ, 1972, P I MECH ENG, V186, P519 RICHARDSON JH, 1979, 791234 AIAA ROSNER DE, 1979, COMBUST SCI TECHNOL, V20, P87 ROSNER DE, 1982, J ENG GAS TURB POWER, V104, P885 SCHMUCKER J, 1994, AGARDCP558 SHELDON GL, 1970, J BASIC ENG, V89, P619 SIRS RC, 1994, AGARDCP558 SMITH HCG, 1952, THEORETICAL NOTE MEC, V145 SMITH J, 1967, 6920 US DEP INT BUR SMITH WS, 1985, 850101 AIAA SUGANO H, 1982, STUDY ASH EROSION AX, V19 TABAKOFF W, 1971, J AIRCRAFT, V8, P60 TABAKOFF W, 1974, 74639 AIAA TABAKOFF W, 1979, ASTM STP, V664, P123 TABAKOFF W, 1980, P ASME S POL FLOW TR, P203 TABAKOFF W, 1986, REV MAT EROSION EXPO TABAKOFF W, 1987, AIAA J, V25, P721 TABAKOFF W, 1987, J FLUIDS ENG, V109, P297 TABAKOFF W, 1987, J TURBOMACH, V109, P535 TABAKOFF W, 1988, 880366 AIAA TABAKOFF W, 1988, J TURBOMACH, V110, P258 TABAKOFF W, 1988, LECT SERIES PUBL, P34 TABAKOFF W, 1990, 902016 AIAA TABAKOFF W, 1990, J TURBOMACH, V112, P78 TABAKOFF W, 1991, J ENG GAS TURB POWER, V113, P607 TABAKOFF W, 1991, J PROPUL POWER, V7, P805 TABAKOFF W, 1991, LASER ANEMOMETRY ADV, P775 TABAKOFF W, 1996, J PROPUL POWER, V12, P260 TABAKOFF W, 2002, 20022373 AIAA TAYLOR GI, 1940, 2024 BRIT AER RES CO TILLY GP, 1973, WEAR, V23, P87 ULKE A, 1976, 76GT74 ASME WAKEMAN T, 1982, 82GT170 ASME WENGLARZ RA, 1981, J ENG POWER, V103, P552 WENGLARZ RA, 1990, J ENG GAS TURB POWER, V112, P9 WENGLARZ RA, 2003, 1009173 EPRI NR 85 TC 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAR-APR PY 2006 VL 22 IS 2 BP 350 EP 360 PG 11 SC Engineering, Aerospace GA 022WO UT ISI:000236087000008 ER PT J AU Chaviaropoulos, PK Politis, ES Lekou, DJ Sorensen, NN Hansen, MH Bulder, BH Winkelaar, D Lindenburg, C Saravanos, DA Philippidis, TP Galiotis, C Hansen, MOL Kossivas, T TI Enhancing the damping or wind turbine rotor blades, the DAMPBLADE project SO WIND ENERGY LA English DT Article DE structural damping; modelling damping; aeroelastic stability; composites ID DAMPED DYNAMIC CHARACTERISTICS; VISCEL PROJECT; MECHANICS AB A research programme enabling the development of damped wind turbine blades, having the acronym DAMPBLADE, has been supported by the EC under its 5th Framework Programme. In DAMPBLADE the following unique composite damping mechanisms were exploited aiming to increase the structural damping: tailoring of laminate damping anisotropy, damping layers and damped polymer matrices. Additional objectives of the project were the development of the missing critical analytical technologies enabling the explicit modelling of composite structural damping and a novel 'composite blade design capacity' enabling the direct prediction of aeroelostic stability and fatigue life, the development and characterization of damped composite materials, and the evaluation of new technology via the design and fabrication of damped prototype blades and their full-scale laboratory testing. After 4 years of work a 19 m glass/polyester damped blade was designed, manufactured and tested using the know-how acquired. Modal analysis of this blade at the testing facility of CRES showed a nearly 80% increase in the damping ratio of both the first Rap and log modes compared with the earlier, standard, design practice. C1 CRES, GR-19009 Pikermi, Greece. Riso Natl Lab, DK-4000 Roskilde, Denmark. Energy Res Ctr Netherlands, ECN, NL-1755 ZG Petten, Netherlands. Univ Patras, Dept Mech Engn & Aeronaut, GR-26500 Patras, Greece. FORTH, ICE, HT, GR-26500 Patras, Greece. Tech Univ Denmark, DK-2800 Lyngby, Denmark. Geobiologiki SA GEO, GR-13671 Athens, Greece. RP Politis, ES, CRES, 19th Km Marathonos Ave, GR-19009 Pikermi, Greece. EM vpolitis@cres.gr CR CHAVIAROPOULOS PK, 2000, J FLUID ENG-T ASME, V122, P330 CHAVIAROPOULOS PK, 2001, WIND ENERGY, V4, P183 CHAVIAROPOULOS PK, 2003, WIND ENERGY, V6, P365, DOI 10.1002/we.100 CHAVIAROPOULOS PK, 2003, WIND ENERGY, V6, P387, DOI 10.1002/we.101 CHRYSOCHOIDIS NA, 2004, 11 EUR C COMP MAT RH HANSEN MH, 2004, WIND ENERGY, V7, P133, DOI 10.1002/we.116 LEKOU DJ, 2001, P EWEC 2001, P287 LEKOU DJ, 2005, TPR 8 TEST PROCEDURE LINDENBURG C, 2003, ECNC02050 MENTER FR, 1993, 932906 AIAA MICHELSEN JA, 1992, 9205 AFM TU DENM MICHELSEN JA, 1998, 9801 ETAFM TU DENM PLAGIANAKOS TS, 2003, J SOUND VIB, V263, P399 PLAGIANAKOS TS, 2004, INT J SOLIDS STRUCT, V41, P6853, DOI 10.1016/j.ijsolstr.2004.05.038 SARAVANOS DA, 1990, AIAA J, V28, P1813 SARAVANOS DA, 1990, J COMPOS TECH RES, V12, P31 SARAVANOS DA, 1992, ASTM SPECIAL TECHNIC, V1169, P471 SARAVANOS DA, 1995, J VIB ACOUST, V117, P62 SARAVANOS DA, 2003, P 2003 EUR WIND EN C SARAVANOS DA, 2005, IN PRESS J SOUND VIB SNEL H, 1992, 18 EUR ROT FOR AV, B10 SORENSEN NN, 1995, RISOR827EN RIS NAT L NR 22 TC 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1095-4244 J9 WIND ENERGY JI Wind Energy PD JAN-APR PY 2006 VL 9 IS 1-2 BP 163 EP 177 PG 15 SC Energy & Fuels; Engineering, Mechanical GA 015MQ UT ISI:000235555900014 ER PT J AU Almeida, DS Silva, CRM Nono, MCA Cairo, CAA TI EB-PVD TBCs of zirconia co-doped with yttria and niobia, a microstructural investigation SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE SEM; X-ray diffraction; electron beam evaporation; niobium oxide; zirconium oxide ID THERMAL BARRIER COATINGS; TETRAGONAL ZRO2; PHASE-STABILITY; SYSTEMS AB Turbine blades of airplanes and thermoelectric plants work in adverse conditions, with corrosive environment and high temperature and pressure. One way to improve the life and/or the working temperature of the blades is the use of special coatings over metallic material applied by Electron Beam-Physical Vapor Deposition (EB-PVD). The most usual material for this application is yttria doped zirconia. Addition of mobia, as a co-dopant in the Y2O3-ZrO2 system, can reduce the thermal conductivity and improve mechanical properties of the coating. The purpose of this work is to show the influence of the addition of niobia on the microstructure of ceramic coatings by using X-ray diffraction (XRD) techniques and scanning electron microscopy (SEM) observations. SEM on fractured cross-section shows a columnar structure and the results of XRD show only zirconia tetragonal phase in the ceramic coating for the chemical composition range studied. As the difference (NbO2.5-YO1.5) mol% increases, the ratio c/a (tetragonality) increases. Considering that the t-ZrO2 solid solutions begins unstable when the relation c/a exceeds 1.020, it is possible to evaluate the maximum niobia content that can be added to the coating without losses in its mechanical properties. SEM on ceramic coatings polished cross-section shows color bands associated with chemical composition changes due to the differences in saturation vapor pressure of the individual components. As the niobia content increases, there is a tendency to reduction of the ceramic coating theoretical density. (c) 2005 Elsevier B.V. All rights reserved. C1 AMR CTA, Div Mat, Ctr Tecn Aeroespacial, BR-12228904 Sao Jose Dos Campos, Brazil. INPE, LAS, Sao Jose Dos Campos, SP, Brazil. RP Almeida, DS, AMR CTA, Div Mat, Ctr Tecn Aeroespacial, Pca Marechal Ar Eduardo Gomes,50, BR-12228904 Sao Jose Dos Campos, Brazil. EM dsa62@yahoo.com CR ALMEIDA DS, 2002, AN C BRAS ENG CIEN M BERNIER JS, 2003, SURF COAT TECH, V95, P163 COUTO P, 2003, FLASH METHOD STANDAR CZEK N, 1999, SURF COAT TECH, V113, P157 EVANS AG, 2001, PROG MATER SCI, V46, P249 GOWARD GW, 1998, SURF COAT TECH, V108, P73 GUO HB, 2001, SCRIPTA MATER, V44, P683 GUO X, 1998, J EUR CERAM SOC, V18, P237 HASS DD, 2001, THESIS U VIRGINIA MA HENKE BL, 1993, ATOM DATA NUCL DATA, V54, P181 HILLERY RV, 1996, COATINGS HIGH TEMPER KIM DJ, 1990, J AM CERAM SOC, V73, P115 KIM DJ, 1991, J AM CERAM SOC, V74, P3061 LEE DY, 1998, J MATER SCI LETT, V17, P185 LEHMANN H, 2003, J AM CERAM SOC, V86, P1138 LELAIT L, 1993, J PHYS IV, V3, P645 LEYENS C, 1999, SURF COAT TECH, V120, P68 LI P, 1994, J AM CERAM SOC, V77, P1281 MUMM DR, 2001, ACTA MATER, V49, P2329 NICHOLLS JR, 1999, WEAR, V233, P352 RAGHAVAN S, 1998, SCRIPTA MATER, V39, P1119 RAGHAVAN S, 2001, ACTA MATER, V49, P169 ROTH RS, 1964, PHASE DIAGRAMS CERAM SCHULZ U, 2000, SURF COAT TECH, V133, P40 SCHULZ U, 2003, AEROSP SCI TECHNOL, V7, P73 STOVER D, 1999, J MATER PROCESS TECH, V92, P195 VASINONTA A, 2001, ENG FRACT MECH, V68, P843 VYAS JD, 2000, MAT SCI ENG A-STRUCT, V277, P206 XU HB, 1998, THIN SOLID FILMS, V334, P98 ZHU D, NASATM2000210238 NR 30 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JAN 24 PY 2006 VL 200 IS 8 BP 2827 EP 2833 PG 7 SC Materials Science, Coatings & Films; Physics, Applied GA 010NT UT ISI:000235202100031 ER PT J AU Harig, T TI Modernization of turbines in nuclear power plants SO ATW-INTERNATIONAL JOURNAL FOR NUCLEAR POWER LA English DT Article AB An ongoing goal in the power generation industry is to maximize the output of currently installed assets. This is most important at nuclear power plants due to the large capital, investments that went into these plants and their base loaded service demands. Recent trends in the United States show a majority of nuclear plants are either obtaining, or are in the process of obtaining NRC approvals for operating license extensions and power uprates. This trend is evident in other countries as well. For example, all Swedish nuclear power plants are currently working on projects to extend their service life and maximize capacity through thermal uprate and turbine-generator up-grade with newest technology. The replacement of key components with improved ones is a means of optimizing the service life and availability of power plants. Economic advantages result from increased efficiency, higher output, shorter startup and shutdown times as well as reduced outage times and service costs. The rapid advances over recent years in the development of calculation programs enables adaptation of the latest blading technology to the special requirements imposed by steam turbine upgrading. This results in significant potential for generating additional output with the implementation of new technology, even without increased thermal power. In contrast to maintenance and investment in pure replacement or repair of a component with the primary goal of maintaining operability and reliability, the additional output gained by upgrading enables a return on investment to be reaped. C1 Siemens AG Power Generat, D-91058 Erlangen, Germany. RP Harig, T, Siemens AG Power Generat, Freyeslebenstr 1, D-91058 Erlangen, Germany. NR 0 TC 0 PU VERLAGSGRP HANDELSBLATT GMBH PI DUSSELDORF PA POSTFACH 10 11 02, D-40002 DUSSELDORF, GERMANY SN 1431-5254 J9 ATW-INT J NUCL POWER JI ATW-Int. J. Nucl. Power PD NOV PY 2005 VL 50 IS 11 BP 652 EP + PG 6 SC Nuclear Science & Technology GA 007TZ UT ISI:000234994100004 ER PT J AU Aguero, A Garcia, M Gutierrez, M TI Low temperature MOCVD process for fast aluminium deposition on metallic substrates SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; COATINGS; STEELS AB A CVD pilot plant, designed and built in INTA, is presently being used to deposit aluminium coatings with applications in the fields of industrial and aeronautic turbines, as well as on the protection of components employed in the chemical industry, waste incinerators, fuel cells, and for the replacement of Cd coatings in aeronautic components. The industrial process currently used to coat aeronautic and industrial turbine components employs AlCl3 as precursor at 700-1100 degrees C and requires more than 12 h per batch (including loading, heating, coating and cooling) due to the relatively low deposition rates and the long heating and cooling cycles. The new process carried out at INTA employs an organometallic precursor, which results in higher deposition rates, at 280-350 degrees C with a total processing time lower than 5 h per batch. As in any other CVD process, this one allows deposition of coatings in complex geometry components such as on the inner surfaces of turbine blades and heat exchangers tubes. Other important advantages of this particular process are the possibility of recovering and re-utilising the unreacted precursor as well as the high purity of the produced coatings in comparison with those produced by other commercially available technologies. It is well known that the higher the contamination degree, the lower the useful life of this type of coatings. The pilot plant has a deposition chamber with a useful coating zone of 30 cm in length and 18 cm in diameter, heated by a three zone furnace equipped with a pumping system that allows working pressures of 0.1 - 100 mbar. The system can be manually or automatically controlled and can be easily adapted to deposit other materials. By heat treating the pure Al coatings deposited on Ni base superalloys, Ni aluminide coatings have been obtained and excellent cyclic oxidation behaviour has been observed at 1000 degrees C. Al has also been deposited on ferritic steels (P91 and 92) and after a suitable heat treatment Fe aluminide coatings with excellent steam oxidation resistance have been obtained. Another potential important use of this process is the deposition of dense aluminium coatings for cadmium replacement in several industrial applications. C1 INTA, Area Mat Met, Torrejon de Ardoz 28850, Madrid, Spain. RP Aguero, A, INTA, Area Mat Met, Ctra Ajalvir Km 4, Torrejon de Ardoz 28850, Madrid, Spain. EM agueroba@inta.es CR AGUERO A, 2002, MAT ADV POWER ENG, P1143 AGUERO A, 2004, MATER SCI FORUM, V461, P957 DUMITRESCU L, 2000, SURF COAT TECH, V125, P419 KNOEDLER R, 2001, P BALTICA 5 C PORV J, P355 KODAS T, 1994, CHEM METAL CVD, P48 LEGG KO, 2002, SURFACE MODIFICATION, P1 LIBURDI J, 2000, P ASME TURBO EXPO 20 RESTALL JE, 1986, MATER SCI TECH SER, V2, P225 WARNES BM, 1997, SURF COAT TECH, V94, P1 XIANG ZD, 2004, SURF COAT TECH, V184, P108, DOI 10.1016/j.surfcoat.2003.10.046 NR 10 TC 4 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD DEC PY 2005 VL 56 IS 12 BP 937 EP 941 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 000LF UT ISI:000234462600013 ER PT J AU Rinaldi, C Bicego, V Colombo, PP TI Validation of CESI blade life management system by case histories and in situ NDT SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB A life management system was developed for hot components of large industrial gas turbines, in the form of a software tool for predicting component lives under typical operational transients (normal and also abnormal) and steady-state periods. The method utilizes results of previous thermo-mechanical finite element and finite volume fluid mechanics analyses. The basic idea of this method is using data from structural and aerothermal analyses (pressures and temperatures), blade life theory and material properties as an input to algorithms, and using operational and historical data to validate the predicted damage amounts. The software developed in this project, of general applicability to all GT models, has been. implemented with reference to the geometries, materials, and service conditions of a Fiat-Westinghouse model. C1 CESI, I-20134 Milan, Italy. RP Rinaldi, C, CESI, Via Rubattino 54, I-20134 Milan, Italy. CR ANTONELLI G, 1997, 97GT1 ASME ANTONELLI G, 1998, 7 EUR C NDT COP ANTONELLI G, 2000, POW GEN EUR 2000 HEL ANTONELLI G, 2003, TURB FOR NIC FRANC BERNSTEIN HL, 1990, P INT C LIF ASS REP, P111 BERSTEIN HL, 1993, ASTM STP, V1186, P212 CHAN KS, 1998, 98GT478 ASME CHAN KS, 1999, J ENG GAS TURB POWER, V121, P484 COLOMBO PP, 2001, P EUROMAT 2001 C MAT LOWELL CE, 1991, OXID MET, V36, S1 MANDELLI M, 2003, THESIS TRENTO U ITAL NESBITT JA, 2000, NASATM2000209271 SRINIVASAN V, 1995, MATER MANUF PROCESS, V10, P955 SVAMINATHAN VP, 1996, 96GT528 ASME VISWANATHAN R, 1999, INT C LIF ASS GAS TU NR 15 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2006 VL 128 IS 1 BP 73 EP 80 PG 8 SC Engineering, Mechanical GA 996RR UT ISI:000234192600010 ER PT S AU Almeida, DS Silva, CRM Nono, MCA Cairo, CAA TI Electron beam-physical vapour deposition of zirconia co-doped with yttria and niobia SO ADVANCED POWDER TECHNOLOGY IV SE MATERIALS SCIENCE FORUM LA English DT Article DE EB-PVD; TBC; zirconia; niobia ID THERMAL BARRIER COATINGS; EB-PVD; TETRAGONAL ZRO2; PHASE-STABILITY; SYSTEM AB Turbine blades of airplanes and thermoelectric plants work in adverse conditions, with corrosive environment and high temperature and pressure. One way to improve the life or the working temperature of the blades is by the use of special coatings over metallic material applied by Electron Beam - Physical Vapour Deposition (EB-PVD). The most usual material for this application is zirconia doped with yttria. Addition of niobia, as a co-dopant in the Y2O3-ZrO2 system, can reduce the thermal conductivity and improve mechanical properties of the coating. The purpose of this work is to show the influence of the addition of niobia on microstructure of ceramic coating taking in to consideration X-ray diffraction and scanning electron microscopy observations. First result shows a columnar structure with only tetragonal phase in the ceramic coating in the chemical composition range studied. C1 Ctr Tecn Aeroesp, Inst Aeronaut & Espaco, Sao Jose Dos Campos, Brazil. Inst Nacl Pesquisas Espaciais, Lab Mat & Sensores, Sao Jose Dos Campos, Brazil. RP Almeida, DS, Ctr Tecn Aeroesp, Inst Aeronaut & Espaco, Sao Jose Dos Campos, Brazil. EM dsa62@yahoo.com CR ALMEIDA DS, 2002, AN C BRAS ENG CIENC CZEK N, 1999, SURF COAT TECH, V113, P157 EVANS AG, 2001, PROG MATER SCI, V46, P249 GOWARD GW, SURFACE COATING TECH, V18, P73 GUO X, 1998, J EUR CERAM SOC, V18, P237 HASS DD, 2001, THESIS U VIRGINIA KIM DJ, 1990, J AM CERAM SOC, V73, P115 KIM DJ, 1991, J AM CERAM SOC, V74, P3061 LEE DY, 1998, J MATER SCI LETT, V17, P185 LELAIT L, 1993, J PHYS IV, V3, P645 LEYENS C, 1999, SURF COAT TECH, V120, P68 LI P, 1994, J AM CERAM SOC, V77, P1281 MUMM DR, 2001, ACTA MATER, V49, P2329 NICHOLLS JR, 1999, WEAR, V233, P352 RAGHAVAN S, 2001, ACTA MATER, V49, P169 ROTH RS, 1964, PHASE DIAGRAMS CERAM, V1, P144 SCARDI P, 2001, J AM CERAM SOC, V4, P827 SCHULZ U, 1996, SURF COAT TECH, V82, P259 SCHULZ U, 2000, SURF COAT TECH, V133, P40 STOVER D, 1999, J MATER PROCESS TECH, V92, P195 XU HB, 1998, THIN SOLID FILMS, V334, P98 ZHU D, NASATM2000210238 NR 22 TC 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2005 VL 498-499 BP 453 EP 458 PG 6 SC Materials Science, Multidisciplinary GA BDK21 UT ISI:000233984500073 ER PT J AU Perkins, KM Bache, MR TI Corrosion fatigue of a 12%Cr low pressure turbine blade steel in simulated service environments SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE corrosion fatigue; 12%Cr stainless steel; pitting; power generation ID AUSTENITIC STAINLESS-STEEL; CRACK-PROPAGATION; PITTING CORROSION; GROWTH; INCLUSIONS AB An investigation has been carried out to examine the corrosion fatigue performance of a 12%Cr stainless steel in simulated service environments. Uniaxial, constant amplitude load control fatigue tests were performed in de-ionized water at 120 degrees C with zero and 4 ppm oxygen, zero and 1 ppm chloride. The effect of frequency is also examined and its effect on the fatigue life of the material is discussed. The results showed that when compared with air data at the same temperature the fatigue strength is reduced, the reduction being greater with increasing oxygen content. Although no evidence of pitting was found in the zero and 4 ppm oxygen environments, some differences were found in the fracture appearance, which are discussed. Failure in chloride containing environments was found to occur from corrosion pits, although the application of a stress was found to be a necessary part of the initiation process. Static load tests indicated that this stress needed to be cyclic, suggesting the dominant failure mechanism is that of corrosion fatigue. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Coll Swansea, Sch Engn, Mat Res Ctr, Swansea SA2 8PP, W Glam, Wales. RP Perkins, KM, Univ Coll Swansea, Sch Engn, Mat Res Ctr, Singleton Pk, Swansea SA2 8PP, W Glam, Wales. EM k.m.perkins@swan.ac.uk CR 1984, CS2932 EPRI *EL POW RES I, 1985, CS3891 EPRI ATKINSON JD, 1979, MET SCI, V13, P444 AUSTEN IM, 1979, MET SCI, V13, P420 BARSOM JM, 1972, NACE242436 BARSOM JM, 1977, FRATURE FATIGUE CONT BROWN F, FIRB19 ENDO K, 1972, NACE243750 HOLDSWORTH S, 2002, P EPRI C ADV LIF ASS JAKUBOWSKI M, 1998, FATIGUE FRACT ENG M, V21, P937 MCMAHON CJ, 1968, ASTM STP, V407, P127 MCMAHON CJ, 2001, ENG FRACT MECH, V68, P773 MURTAZA G, 1996, INT J FATIGUE, V18, P557 PARK JO, 2000, ELECTROCHEM SOLID ST, V3, P416 PERKINS KM, IN PRESS INT J FATIG SHIPILOV SA, 2002, FATIGUE FRACT ENG M, V25, P243 SPARKES GM, MIDSSD810015R CEGB STEVEN W, 1959, J IRON STEEL I, V193, P141 STEWART J, 1992, CORROS SCI, V33, P457 SURESH S, 1982, MET SCI, V16, P529 TOMKINS B, 1979, MET SCI, V13, P387 WEBB KM, 2003, THESIS SWANSEA WILLIAMS DE, 1994, CORROS SCI, V36, P1213 WILLIAMS G, PRIVATE DATA WILLIAMS G, UNPUB PITTING CORROS NR 25 TC 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD OCT-DEC PY 2005 VL 27 IS 10-12 BP 1499 EP 1508 PG 10 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 986ZD UT ISI:000233487300045 ER PT J AU Hutson, A Nicholas, T John, R TI Fretting fatigue crack analysis in Ti-6Al-4V SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE fretting fatigue; stress intensity; crack growth; titanium AB A study was conducted to verify the efficacy of a fracture mechanics methodology to model the crack growth behavior of fretting fatigue-nucleated cracks obtained under test conditions similar to those found in turbine engine blade attachments. Experiments were performed to produce cracked samples, and fretting fatigue crack propagation lives were calculated for each sample. Cracks were generated at 106 Cycles (10%-of-life) under applied stress conditions previously identified as the fretting fatigue limit conditions for a 107 cycle fatigue life. Resulting cracks, ranging in size from 30 to 1200 Inn, were identified and measured using scanning electron microscopy. Uniaxial fatigue limit stresses were determined experimentally for the fretting fatigue-cracked samples, using a step loading technique, for R=0.5 at 300 Hz. Fracture surfaces were inspected to characterize the fretting fatigue crack front indicated by heat tinting. The shape and size of the crack front were then used in calculating Delta Kth values for each crack. The resulting uniaxial fatigue limit and Delta Kth values compared favorably with the baseline fatigue strength (660 MPa) for this material and the Delta Kth value (2.9 MPa root m) for naturally initiated cracks tested at R=0.5 on a Kitagawa diagram. Crack propagation lives were calculated using stress results of FEM analysis of the contact conditions and a weight function method for determination of Delta K. Resulting lives were compared with the nine million-cycle propagation life that would have been expected in the experiments, if the contact conditions had not been removed. Scatter in the experimental results for fatigue limit stresses and fatigue lives had to be considered as part of an explanation why the fatigue life calculations were unable to match the experiments that were modeled. Analytical life prediction results for the case where propagation life is observed to be very short experimentally were most accurate when using a coefficient of friction, mu = 1.0, rather than for the calculations using mu = 0.3 (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Inst Technol, ENY, AFIT, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Mat & Mfg Directorate, MLLMN, Wright Patterson AFB, OH 45433 USA. RP Hutson, A, Univ Dayton, Res Inst, Dayton, OH 45469 USA. EM alisha.hutson@wpafb.af.mil CR ATTIA MH, ASTM STP, V1159 CONNER BP, 2003, WEAR 1, V255, P259, DOI 10.1016/S0043-1648(03)00152-2 GALLAGHER JP, 2001, AFRLMLWPTR20014159 U GOLDEN PJ, 2004, INT J FATIGUE, V26, P281, DOI 10.1016/S0142-1123(03)00166-X HARTER JA, 1999, AFRLVAWPTR19993016 HOEPPNER DW, ASTM STP, V1367 HUTSON A, 2003, TRIBOL INT, V36, P133 HUTSON AL, IN PRESS TRIBOL INT HUTSON AL, 1999, INT J FATIGUE, V21, P663 HUTSON AL, 2000, THESIS U DAYTON DAYT HUTSON AL, 2001, INT J FATIGUE S1, V23, P445 HUTSON AL, 2002, ASTM STP, V1425, P307 HUTSON AL, 2004, EXP MECH, V45, P160 HUTSON AL, 2004, P 10 WORLD C TIT HAM, P1707 KINYON SE, ASTM STP, V1425 MAXWELL DC, 1999, ASTM STP, V1321, P626 MOSHIER MA, 2002, ASTM STP, V1413, P129 NABOULSI S, 2003, INT J SOLIDS STRUCT, V40, P6497, DOI 10.1016/S0020-7683(03)00401-3 NICHOLAS T, 2003, INT J FATIGUE, V25, P1069, DOI 10.1016/S0142-1123(03)00115-4 NICHOLAS T, 2004, UDRTR200300115 U DAY WATERHOUSE RB, 1994, MECH ENG PUBLICATION NR 21 TC 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD OCT-DEC PY 2005 VL 27 IS 10-12 BP 1582 EP 1589 PG 8 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 986ZD UT ISI:000233487300055 ER PT J AU Wu, J Ngyuen, B Graham, L Zhu, Y Kilpatrick, T Davis, J TI Minimizing impeller slurry wear through multilayer paint modelling SO CANADIAN JOURNAL OF CHEMICAL ENGINEERING LA English DT Article DE slurry mixing impeller erosion; multilayer paint modelling; vortex-induced wear ID EROSION AB The present paper describes an experimental study using a multilayer paint technique to illustrate the wear patterns developed on an eight-bladed disc turbine in a gas/liquid/solids three-phase mixing tank. A distinctive wear pattern was found to develop on the low-pressure side of the blades. The patterns were found to be caused by the two intersecting vortices that developed along the blades. Several modifications were made to the impeller geometry to reduce wear. A new impeller design, which experienced a lower wear rate and showed an improved off bottom solids suspension performance, is recommended for operating in gas/liquid/solids reactors. C1 CSIRO, Fluids Engn, Highett, Vic 3190, Australia. Rio Tinto TS, Bundoora, Vic 3083, Australia. RP Wu, J, CSIRO, Fluids Engn, Highett, Vic 3190, Australia. EM jie.wu@csiro.au CR AHMAD K, 1986, IMECHE, V200, P439 BLAU PJ, 1997, TRIBOL INT, V30, P321 DEUIS RL, 1996, WEAR, V201, P132 FINNIE I, 1995, WEAR, V186, P1 FORT I, 1999, ICHEME S SER, V146, P59 HUMPHREY JAC, 1990, INT J HEAT FLUID FL, V11, P170 HUTCHINGS IM, 1987, CHEM ENG SCI, V42, P869 LAITONE JA, 1979, WEAR, V56, P239 OMOTE T, 1995, P 27 INT SAMPE TECHN, V27, P104 PARSLOW GI, 1997, WEAR, V212, P103 STOOTS CM, 1995, AICHE J, V41, P1 VANTRIET K, 1975, CHEM ENGNG SCI, V30, P1093 WALKER CI, 2001, WEAR 1, V250, P81 WALKER CI, 2002, P HYDR BANFF CAN JUN, V15, P725 WEETMAN RJ, 1998, J MATER ENG PERFORM, V7, P491 WU J, 2001, CAN J CHEM ENG, V79, P177 YIANNESKIS M, 1987, J FLUID MECH, V175, P537 ZHANG Y, 2000, WEAR, V240, P40 NR 18 TC 2 PU CANADIAN SOC CHEMICAL ENGINEERING PI OTTAWA PA 130 SLATER ST, STE 550, OTTAWA, ONTARIO K1P 6E2, CANADA SN 0008-4034 J9 CAN J CHEM ENG JI Can. J. Chem. Eng. PD OCT PY 2005 VL 83 IS 5 BP 835 EP 842 PG 8 SC Engineering, Chemical GA 986BE UT ISI:000233422700005 ER PT S AU Kim, CS Kim, JK Kim, TS TI An evaluation of appropriate probabilistic S-N curve for the turbine blade steel in the low pressure steam SO ADVANCES IN FRACTURE AND STRENGTH, PTS 1- 4 SE KEY ENGINEERING MATERIALS LA English DT Article DE correlation coefficient; coefficient of skewness; error-para meter; log-normal distribution; Weibull distribution; probabilistic S-N curve; optimization technique AB In order to evaluate the variation of fatigue data of turbine blade steel in low pressure (LP) steam, it is important to estimate probabilistic stress-life (P-S-N) curve to accurately define the probability distribution. In this study, a new procedure was introduced to determine the expression of P-S-N curves. For this purpose, 3-parameter Weibull distribution was found to be the most appropriate among assumed distributions when the probability distributions of the fatigue life were examined by a comparative analysis. Furthermore, the parameter of P-S-N curve was evaluated using various optimization techniques to maximize the correlation coefficient. As a result, the sequential linear program method is used for estimation of P-S-N curve. C1 Hanyang Univ, Sch Mech Engn, Seoul, South Korea. EM chalskim@paran.com kimj@hanyang.ac.kr ktaeseong@hanmail.net CR *ASTM, 1991, 73991 ASTM E *JSME, 1994, 002 JSME S, P8 *VR D INC, 1999, DOT DES OPT TOOLS JOHN R, 1996, METAL HDB 9 EDITION, V8 KECECIOGLU DB, 1993, RELIABILITY LIFE TES, V1 KIM CS, 2002, KSME A, V26, P2421 LING J, 1997, INT J FATIGUE, V19, P415 LITTLE RE, 1972, ASTM STP, V511, P29 NAKAZAWA F, 1987, STAT RES FATIGUE FRA NISHIJIMA S, 1987, STAT ANAL SMALL SAMP, P1 WEIBULL W, 1961, FATIGUE TESTING ANAL ZHAO YX, 1998, FATIGUE FRACT ENG M, V21, P781 ZHAO YX, 2000, RELIAB ENG SYST SAFE, V12, P1 NR 13 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2005 VL 297-300 PN Part 1-4 BP 1751 EP 1757 PG 7 SC Materials Science, Ceramics; Materials Science, Composites GA BDE59 UT ISI:000233131202049 ER PT J AU Sidwell, V Darmofal, D TI The impact of blade-to-blade flow variability on turbine blade cooling performance SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB The focus of this paper is the impact of manufacturing variability oil turbine blade cooling flow and, subsequently, its impact oil oxidation life. A simplified flow network model of the cooling air supply system and a row of blades is proposed. Using this simplified model, the controlling parameters which affect the distribution of cooling flow in a blade row are identified. Small changes in the blade flow tolerances (prior to assembly of the blades into a row) are shown to have a significant impact oil the minimum flow observed in a row of blades resulting in substantial increases in the life of a blade row. A selective assembly method is described in which blades are classified into a low-flow and a high-flow, group based oil passage flow capability (effective areas) in life-limiting regions and assembled into rows from within the groups. Since assembling rows from only high-flow blades is equivalent to raising the low-flow tolerance limit, high-flow blade rows will have the same improvements in minimum flow and life that would result from more stringent tolerances. Furthermore, low-flow blade rows are shown to have minimum blade flows which are the same or somewhat better than a low-flow blade that is isolated in a row of otherwise higher-flowing blades. As a result, low-flow blade rows are shown to have lives that are no worse than random assembly from the full population. Using a higher fidelity model for the auxiliary air system of an existing jet engine, the impact of selective assembly on minimum blade flow and life of a row is estimated and shown to be in qualitative and quantitative agreement with the simplified model analysis. C1 Pratt & Whitney, Multidisciplinary Design & Optimizat Grp, E Hartford, CT 06109 USA. MIT, Cambridge, MA 02139 USA. RP Sidwell, V, Pratt & Whitney, Multidisciplinary Design & Optimizat Grp, 400 Main St,M-S 165-16, E Hartford, CT 06109 USA. CR CYRUS JD, 1986, 86GT24 ASME HOLLAND MJ, 1980, J AIRCRAFT, V17, P412 LIU Z, 2002, AIAA20021277 SIDWELL CV, 2004, THESIS MIT SIDWELL V, 2003, 10717408, US SIDWELL V, 2003, GT200338119 ASME SIDWELL V, 2004, GT200453930 ASME SUO M, 1978, AFAPLTR7852 SWAMINATHAN VP, 1986, 96GT528 ASME TURNER IY, 1999, AIAA992850 WOOD MI, 2000, P I MECH ENG A-J POW, V214, P193 NR 11 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD OCT PY 2005 VL 127 IS 4 BP 763 EP 770 PG 8 SC Engineering, Mechanical GA 981XL UT ISI:000233121200013 ER PT J AU Sutherland, HJ Mandell, JF TI Optimized constant-life diagram for the analysis of fiberglass composites used in wind turbine blades SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB Mandell et al. have recently presented an updated constant-life diagram (CLD) for a fiberglass composite that is a typical wind turbine blade material. Their formulation uses the MSU/DOE fatigue data base to develop a CLD with detailed S-N information at 13 R-values. This diagram is the most detailed to date, and it includes several loading conditions that have been poorly represented in earlier studies. Sutherland and Mandell have used this formulation to analyze typical loads data from operating wind farms and the,failure of coupons subjected to spectral loading. The detailed CLD used in these analyses requires a significant investment in materials testing that is usually outside the bounds of typical design standards for wind turbine blades. Thus, the question has become: How many S-N curves are required for the construction of a CLD that is sufficient for an "accurate" prediction of equivalent fatigue loads and service lifetimes? To answer this question, the load data from two operating wind turbines and the failure of coupons tested using the WISPERX spectra are analyzed using a nonlinear damage model. For the analysis, the predicted service lifetimes that are based on the CLD constructed from 13 R-values are compared to the predictions,for CLDs constructed with fewer R-values. The results illustrate the optimum number of R-values is 5 with them concentrated between R-values of -2 and 0.5, or -2 and 0.7. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Montana State Univ, Bozeman, MT 59717 USA. RP Sutherland, HJ, Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM hjsuthe@sandia.gov johnm@coe.montana.edu CR KELLEY N, 2002, 2002 ASME WIND EN S, P412 MANDELL JF, 1997, SAND973002 SAND NAT MANDELL JF, 2003, ICCM14 NIJSSEN RPL, 2002, J SOL ENERG-T ASME, V124, P396, DOI 10.1115/1.1510524 NIJSSEN RPL, 2005, 2005 AIAA ASME WIND, P28 SUTHERLAND HJ, 1999, SAND990089 SAND NAT SUTHERLAND HJ, 2000, 2000 ASME WIND EN S, P413 SUTHERLAND HJ, 2001, 2001 ASME WIND EN S, P162 SUTHERLAND HJ, 2002, J SOL ENERG-T ASME, V124, P432, DOI 10.1115/1.1507763 SUTHERLAND HJ, 2003, 2003 ASME WIND EN S, P214 SUTHERLAND HJ, 2004, 2004 ASME WIND EN S, P140 SUTHERLAND HJ, 2004, SPEC TOP C 2004 SCI, P546 SUTHERLAND HJ, 2005, WIND ENERGY, V8, P93, DOI 10.1002/we.125 TENHAVE AA, 1992, NLRTP146U NAT AER LA WAHL NK, 2002, SAND20020546 SAND NA NR 15 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2005 VL 127 IS 4 BP 563 EP 569 PG 7 SC Energy & Fuels; Engineering, Mechanical GA 982SF UT ISI:000233181200015 ER PT J AU Komazaki, S Shoji, T Takamura, K TI Evaluation of thermal aging embrittlement in directionally solidified Ni-base superalloy by small punch test SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CREEP PROPERTY MEASUREMENT; FERRITIC STEELS; BEHAVIOR AB In order to develop, a procedure for evaluating the degradation of impact toughness in directionally solidified Ni-base superalloy CM247LC, which is commonly used for advanced gas turbine blades, the change in small punch (SP)fracture energy due to thermal aging has been investigated. The SP testing technique has been applied to materials aged under various aging conditions, and correlation with the results of Charpy V-notch impact tests has been examined. The experimental results reveal that SP fracture energy at room temperature decreases with aging at 800 degrees C and is uniquely correlated with high-temperature Charpy impact toughness. The current experiment has shown that the SP testing technique is useful in evaluating the degree of thermal aging embrittlement, one of the parameters required for remaining-life prediction of aged components. C1 Muroran Inst Technol, Dept Mat Sci & Engn, Muroran, Hokkaido 0508585, Japan. Tohoku Univ, Fracture Res Inst, Grad Sch Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. RP Komazaki, S, Muroran Inst Technol, Dept Mat Sci & Engn, 27-1 Mizumoto Cho, Muroran, Hokkaido 0508585, Japan. EM komazaki@mmm.muroran-it.ac.jp CR BAIK JM, 1983, SCRIPTA METALL, V17, P1443 JOO YH, 1992, J TEST EVAL, V20, P6 KAMEDA J, 1986, MATER SCI ENG, V83, P29 KOMAZAI S, 2000, J TEST EVAL, V28, P249 KOMAZAKI S, 1997, METALL MATER TRANS A, V28, P1945 KOMAZAKI S, 1997, METALL MATER TRANS A, V28, P1945 KOMAZAKI S, 2000, JSME INT J A-SOLID M, V43, P156 LEVERANT GR, 1987, RP27754 EL POW RES I MAO X, 1987, J TEST EVAL, V15, P30 MAO XY, 1987, J NUCL MATER, V150, P42 MATSUSHITA T, 1990, P KSME JSME JOINT C, P259 MISAWA T, 1987, J NUCL MATER, V150, P194 PARD AG, 1989, RP27751 EL POW RES I SAUCEDOMUNOZ ML, 2002, J MATER RES, V17, P1945 SAUCEDOMUNOZ ML, 2002, J MATER RES, V17, P852 SIMS CT, 1987, SUPERALLOY, V2 STRINGER J, 1993, P ASM 1993 MAT C ASM, P1 SUSUKIDA H, 1973, MITSUBISHI TECHNICAL, V86 VISWANATHAN R, 1989, DAMAGE MECH LIFE ASS ZHAI PC, 2004, J TEST EVAL, V32, P298 NR 20 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-4289 J9 J ENG MATER TECHNOL JI J. Eng. Mater. Technol.-Trans. ASME PD OCT PY 2005 VL 127 IS 4 BP 476 EP 482 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 976WW UT ISI:000232765200017 ER PT J AU Sato, A Yokokawa, T Koizumi, Y Kobayashi, T Harada, H TI A factor analysis of creep rupture properties of Ni-base superalloys SO JOURNAL OF THE JAPAN INSTITUTE OF METALS LA Japanese DT Article DE nickel-base superalloy; creep life prediction; ruthenium; topologically close packed phase; multi regression analysis AB It is important to clarify the parameters which influence the creep rupture life of Ni-base single crystal superalloys under the service condition of jet-engine turbine blades, such as 1000 degrees C/245 MPa. In the most recently developed alloys, Ru is added to suppress the formation of the detrimental Topologically Close Packed (TCP) phases, however, its solid solution strengthening effects have not been clarified yet. In this study, the parameters affecting the creep rupture life of alloys with various compositions were analyzed by a multi regression method, and the results were discussed quantitatively in terms of the chemical composition of the gamma phase, lattice misfit and volume fraction. It was found that Re, Mo, Ta and W were all effective additions for solid solution strengthening and Re was found to be the most effective under the service condition. In contrast, Ru addition had almost no influence on the strengthening effect. The results enabled the prediction of the creep rupture life of an alloy of a known composition. C1 Natl Inst Mat Sci, Mat Engn Lab, High Temp Mat Grp, Tsukuba, Ibaraki 3050047, Japan. Ishikawajima Harima Heavy Ind Co Ltd, Dept Mat Technol, Res & Engn Div, Tokyo 1888555, Japan. RP Sato, A, Natl Inst Mat Sci, Mat Engn Lab, High Temp Mat Grp, Tsukuba, Ibaraki 3050047, Japan. CR FUJIMURA T, 2004, J GAS TURBINE SOC JA, V32, P174 HARADA H, 1979, TETSU TO HAGANE, V65, P1059 HARADA H, 1988, SUPERALLOYS 1988, P733 KOIZUMI Y, 2003, J JPN I MET, V67, P468 KOIZUMI Y, 2004, SUPERALLOYS 2004, P35 MURAKUMO T, 2004, SUPERALLOYS 2004, P155 NABARRO FRN, 1995, PHYS CREEP, P227 OHARA K, 1996, 5482789A, US SATO A, 2005, 2005 SPR M JAP I MET, P165 WALSTON S, 2004, SUPERALLOYS 2004, P15 YEH AC, 2004, SUPERALLOYS 2004, P677 YOKOKAWA Y, 2004, 149859, JP YOSHIOKA Y, 2004, J GAS TURBINE SOC JA, V32, P130 ZHANG JX, 2002, METALL MATER TRANS A, V33, P3741 ZHANG JX, 2004, SUPERALLOYS, P189 NR 15 TC 2 PU JAPAN INST METALS PI SENDAI PA 1-14-32 ICHIBANCHO AOBA-KU, SENDAI, 980-8544, JAPAN SN 0021-4876 J9 J JPN INST METAL JI J. Jpn. Inst. Met. PD AUG PY 2005 VL 69 IS 8 BP 691 EP 694 PG 4 SC Metallurgy & Metallurgical Engineering GA 962WI UT ISI:000231763500023 ER PT J AU Koizumi, Y Harada, H Kobayashi, T Yokokawa, T TI Long-term creep property of a second-generation nickel-base single-crystal superalloy, TMS-82+ SO JOURNAL OF THE JAPAN INSTITUTE OF METALS LA Japanese DT Article DE nickel-base superalloys; single crystal; second-generation; creep; TMS-82+; Larson-Miller Parameter(LMP) AB Long component-life of at least two years under a daily start and stop condition is required on turbine blades and vanes in land-based power plants. For this reason, a creep rupture life of 10000 hours or longer is required for the application of Ni-base superalloys. In this paper, long-term creep property of more than 15000 hours was analyzed for a second-generation Ni-base superalloy, TMS-82+. Consequently, Larson-Miller parameters in the range of C = 12-14 resulted in good fits over the short-tolong-term creep rupture life, even though C = 20 is conventionally used for Ni-base superalloys. In addition, the creep strength of TMS-82+ exceeds that of CMSX-4 under wide range of stress/temperature conditions, especially under the higher temperature and lower stress condition. C1 Natl Inst Mat Sci, Mat Engn Lab, High Temp Mat Grp, Tsukuba, Ibaraki 3050047, Japan. RP Koizumi, Y, Natl Inst Mat Sci, Mat Engn Lab, High Temp Mat Grp, Tsukuba, Ibaraki 3050047, Japan. CR BULLOUGH CK, 1998, P 6 INT C MAT ADV PO, P861 HARADA H, 1988, SUPERALLOYS 1988, P733 HINO T, 2000, SUPERALLOYS 2000, P729 HINO T, 2002, P 6 INT C MAT ADV PO, P303 NAKAJIMA E, 1997, MAT SCI HIGH TEMPERA, P251 NAKAZAWA S, 1996, 123 COMM HEAT RES MA, V37, P263 ZHANG JX, 2003, ACTA MAT, V52, P5073 NR 7 TC 1 PU JAPAN INST METALS PI SENDAI PA 1-14-32 ICHIBANCHO AOBA-KU, SENDAI, 980-8544, JAPAN SN 0021-4876 J9 J JPN INST METAL JI J. Jpn. Inst. Met. PD AUG PY 2005 VL 69 IS 8 BP 743 EP 746 PG 4 SC Metallurgy & Metallurgical Engineering GA 962WI UT ISI:000231763500036 ER PT J AU Van Paepegem, W Degrieck, J TI Simulating damage and permanent strain in composites under in-plane fatigue loading SO COMPUTERS & STRUCTURES LA English DT Article DE composite; fatigue; damage mechanics; finite element analysis; stiffness ID THERMOMECHANICAL CONSTITUTIVE THEORY; FIBER-REINFORCED COMPOSITES; DISTRIBUTED DAMAGE; ELASTIC COMPOSITES; RESIDUAL STIFFNESS; UNIAXIAL FATIGUE; MATRIX CRACKING; STRENGTH; BEHAVIOR; LIFE AB Fibre-reinforced composites are used in many fatigue-critical applications (wind turbine blades. aircraft components, leaf springs,...). Due to their heterogeneous and anisotropic nature, their fatigue behaviour is rather complex and several damage mechanisms can develop during fatigue life. This paper presents a damage mechanics-based fatigue model for fibre-reinforced plastics, where both stiffness degradation and (possible) accumulation of permanent strain are simulated from the first loading cycle up till final failure. The model has been validated for cantilever bending fatigue tests of plain woven glass/epoxy composite, Although the damage growth rate varies along the specimen length, the finite element simulations with the damage model are able to account for decreasing (bending) stiffness and permanent strain. (c) 2005,Elsevier Ltd. All rights reserved. C1 State Univ Ghent, Dept Mech Construct & Prod, B-9000 Ghent, Belgium. RP Van Paepegem, W, State Univ Ghent, Dept Mech Construct & Prod, St Pietersnieuwstr 41, B-9000 Ghent, Belgium. EM wim.vanpaepegem@ugent.be CR ALLEN DH, 1987, INT J SOLIDS STRUCT, V23, P1301 ALLEN DH, 1987, INT J SOLIDS STRUCT, V23, P1319 BAILLIE JA, 1989, HDB FIBRE COMPOSITES, V2, P353 DEGRIECK J, 2001, APPL MECH REV, V54, P279 DEGRIECK J, 2001, OPT LASER ENG, V36, P29 JEN MHR, 1998, INT J FATIGUE, V20, P605 JEN MHR, 1998, INT J FATIGUE, V20, P617 LAWRENCE WCM, 1993, COMPOS STRUCT, V25, P339 LUBIN G, 1992, AEROSPACE APPL COMPO, P722 PHILIPPIDIS TP, 1999, J COMPOS MATER, V33, P1578 SEDRAKIAN A, 1997, INT C FAT COMP P 3 5, P415 SEDRAKIAN A, 2000, P 2 INT C FAT COMP 4 SHOKRIEH MM, 1997, INT J FATIGUE, V19, P201 SHOKRIEH MM, 1997, INT J FATIGUE, V19, P209 TALREJA R, 1986, ENG FRACT MECH, V25, P751 TALREJA R, 1990, P INT COLL 27 31 AUG, P65 VANPAEPEGEM W, 2001, COMPOS PART B-ENG, V32, P575 VANPAEPEGEM W, 2002, COMP SCI TECHNOL, V63, P305 VANPAEPEGEM W, 2002, COMPOS SCI TECHNOL, V62, P687 VANPAEPEGEM W, 2002, FATIGUE FRACT ENG M, V25, P547 VANPAEPEGEM W, 2002, INT J FATIGUE, V24, P747 VANPAEPEGEM W, 2002, THESIS U ARCH ENG PR NR 22 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD SEP PY 2005 VL 83 IS 23-24 BP 1930 EP 1942 PG 13 SC Computer Science, Interdisciplinary Applications; Engineering, Civil GA 957VK UT ISI:000231401200006 ER PT J AU Cho, SY Cho, TH Choi, SK TI An experimental study of the performance characteristics with four different rotor blade shapes on a small mixed-type turbine SO JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY LA English DT Article DE mixed-type turbine; rotor blade shape; micro-turbine; air tool; turbine performance AB A small mixed-type turbine with a diameter of 19.9 mm has been substituted for a rotational part of pencil-type air tool. Usually, a vane-type rotor is applied to the rotational part of the air tool. However, the vane-type rotor has some problems, such as friction, abrasion, and necessity of accurate assembly etc.,. These problems make the life time of the vane-type air tool short, but air tools operated by mixed-type turbines are free of friction and abrasion because the turbine rotor dose not contact with the casing. Moreover, it is assembled easily because of no axis offset. These characteristics are merits for using air tools, but loss of power is inevitable on a non-contacting type rotor due to flow loss, tip clearance loss, and profile loss etc.,. In this study, four different rotors are tested, and their characteristics are investigated by measuring the specific output power. Additionally, optimum nozzle location against the rotor is studied. Output powers are obtained through measured pressure, temperature, torque, rotational speed, and flow rate. The experimental results obtained with four different rotors show that the rotor blade shape greatly influences to the performance, and the optimum nozzle location exists near the mid span of the rotor. C1 Gyeongsang Natl Univ, Dept Mech & Aerosp Engn, ReCAPT, Jinju 660701, Gyeongnam, South Korea. Korea Inst Mat & Machinery, Dept Adv Ind Technol, Taejon 305343, South Korea. RP Cho, SY, Gyeongsang Natl Univ, Dept Mech & Aerosp Engn, ReCAPT, Jinju 660701, Gyeongnam, South Korea. EM sycho@gsnu.ac.kr CR *LEB PROD, 1998, LOAD CELL TORQ SEN B, V710 *MAGTR INC, 2004, PROD US MAN 2000 200 BALJE OE, 1968, J ENG POWER, P341 BOHN D, 1993, VGB KRAFTWERKSTECHN, V73, P610 BOHN D, 1998, VGB POWERTECH, V2, P49 BOULBIN F, 1994, VDI BERICHTE NR, V1109, P395 CHO SY, 2002, KSME INT J, V16, P1154 CHO SY, 2003, J FLUID MACHINERY, V6, P44 HE L, 1997, P I MECH ENG A-J POW, V211, P197 ROBERT CK, 1949, 1807 NACA SKOPEC J, 1999, IMECHE C T B C, V557, P681 NR 11 TC 2 PU KOREAN SOC MECHANICAL ENGINEERS PI SEOUL PA KSTC NEW BLD. 7TH FLOOR, 635-4 YEOKSAM-DONG KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 1738-494X J9 J MECH SCI TECHNOL JI J. Mech. Sci. Technol. PD JUL PY 2005 VL 19 IS 7 BP 1478 EP 1487 PG 10 SC Engineering, Mechanical GA 953DP UT ISI:000231056900010 ER PT J AU Hohlfeld, EM Christophel, JR Couch, EL Thole, KA TI Predictions of cooling from dirt purge holes along the tip of a turbine blade SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID HEAT-TRANSFER; FLOW AB The clearance gap between the tip of a turbine blade and its associated shroud provides a flow path for leakage from the pressure side of the blade to the suction side. The tip region is one area that experiences high heat transfer and, as such, can be the determining factor for blade life. One method for reducing blade tip heat transfer is to use cooler fluid from the compressor, that exits from relatively large dirt purge holes placed in the tip, for cooling purposes. Dirt purge holes are typically manufactured in the blade tip to extract dirt from the coolant flow through centrifugal forces such that these dirt particles do not block smaller diameter film-cooling holes. This paper discusses the results of numerous computational simulations of cooling injection from dirt purge holes along the tip of a turbine blade. Some comparisons are also made to experimental results in which a properly scaled-up blade geometry (12X) was used to form a two-passage linear cascade. Computational results indicate that the cooling achieved through the dirt purge injection from the blade tip is dependent on the gap size as well as the blowing ratio. For a small tip gap (0.54% of the span) the flow exiting the dirt purge holes act as a blockage for the leakage flow across the gap. As the blowing ratio is increased for a large tip gap (1.63% of the span), the tip cooling increases only slightly while the cooling to the shroud increases significantly. C1 Virginia Polytech Inst & State Univ, Dept Mech Engn, Blacksburg, VA 24060 USA. RP Hohlfeld, EM, Virginia Polytech Inst & State Univ, Dept Mech Engn, Blacksburg, VA 24060 USA. CR *FLUENT INC, 2002, FLUENT US GUID VERS ACHARYA S, GT200230553 AZAD G, 2000GT194 BUNKER RS, 2000, J TURBOMACH, V122, P263 BUNKER RS, 2000, TURB 2000 S HEAT TRA CHYU MK, 1989, J TURBOMACH, V111, P131 KIM YW, 1995, J TURBOMACH, V117, P1 KWAK JS, GT200230194 METZGER DE, 1989, J HEAT TRANS-T ASME, V111, P73 PAPA M, GT200230192 NR 10 TC 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENGINES JI Int. J. Turbo. Jet-Engines PY 2005 VL 22 IS 3 BP 139 EP 152 PG 14 SC Engineering, Aerospace GA 940DL UT ISI:000230123800002 ER PT S AU Krukovsky, P Tadlya, K Rybnikov, A Kolarik, V Stamm, W TI MCrAlY coatings for gas turbine blades life time estimation based on the diffusion-controlled processes moddelling SO DIFFUSION IN MATERIALS: DIMAT 2004, PT 1AND 2 SE DEFECT AND DIFFUSION FORUM LA English DT Article DE gas turbine blades; coatings; life time; oxidation; diffusion; modeling; experiment AB Calculational and experimental approach was developed for life time analysis of MCrAlY coatings for industrial gas turbine blades. This approach based on the model that describes the main diffusion and oxidation processes within the coating-base metal system as well as the experimental data for specimens after different short time exposures at different temperatures. In comparison with existing models the proposed model describes interdiffusion zone between coating and base alloy. The models adequacy to physical processes is provided by model parameters identification with short-time experiment data for coating - base alloy systems. The measured Al concentration profiles were used as input values for the model parameters estimation and a calculational prediction of the long term diffusion and oxidation behaviour of the coating was performed. The model, calculational and experimental approach as well as MCrAlY life time estimation results for 10000 h at 950 degrees C are presented. These results were obtained with short time experimental data for Al concentration profiles across the coating thickness measured after 300 and 1000 h. The predicted and measured beta-phase content at coating during oxidation for coating thickness 200 micron at 900, 950 and 1000 degrees C are presented too. The beta-phase content disappear at coating was assumed as a corrosion life time criterium. C1 Inst Engn Thermophys, UA-03057 Kiev, Ukraine. Polzunov Cent Boiler & Turbine Inst, St Petersburg 194021, Russia. Fraunhofer Inst Chem Technol, D-76327 Pfinztal, Germany. Siemens AG, Power Generat, D-45473 Mulheim, Germany. RP Krukovsky, P, Inst Engn Thermophys, 2A Zhelyabov Str, UA-03057 Kiev, Ukraine. EM kruk@i.kiev.ua rybnicov@online.ru vk@ict.fhg.de CR KRUKOVSKY P, 2001, P EFC WORKSH LIF TIM, P231 KRUKOVSKY PG, 1999, INVERSE PROBL ENG, P403 LEE EY, 1987, SURF COAT TECH, V32, P19 MEIER SM, 1992, T ASME, V114, P250 NESBITT JA, 1995, OXID MET, V44, P309 SIMS CT, 1972, SUPERALLOYS STREIFF R, 1993, J PHYS IV, V3, P17 YOUNG EWA, 1986, OXID MET, V26, P351 NR 8 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1012-0386 J9 DEFECT DIFFUS FORUM PY 2005 VL 237-240 BP 985 EP 990 PG 6 SC Materials Science, Multidisciplinary; Physics, Condensed Matter GA BCN26 UT ISI:000230138400141 ER PT S AU Bedri, R Al-Nais, MO TI Prestressed modal analysis using finite element package ANSYS SO NUMERICAL ANALYSIS AND ITS APPLICATIONS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article DE pre-stress; modal analysis; vibrations; finite elements; ANSYS ID VIBRATIONS AB It is customary to perform modal analysis on mechanical systems without due regards to their stress state. This approach is of course well accepted in general but can prove inadequate when dealing with cases like spinning blade turbines or stretched strings, to name but these two examples. It is believed that the stress stiffening can change the response frequencies of a system which impacts both modal and transient dynamic responses of the system. This is explained by the fact that the stress state would influence the values of the stiffness matrix. Some other examples can be inspired directly from our daily life, i.e., nay guitar player or pianist would explain that tuning of his playing instrument is intimately related to the amount of tension put on its cords. It is also expected that the same bridge would have different dynamic responses at night and day in places where daily temperature fluctuations are severe. These issues are unfortunately no sufficiently well addressed in vibration textbooks when not totally ignored. In this contribution, it is intended to investigate the effect of prestress on the vibration behavior of simple structures using finite element package ANSYS. This is achieved by first performing a structural analysis on a loaded structure then make us of the resulting stress field to proceed on a modal analysis. C1 Coll Technol Hail, Hail, Saudi Arabia. RP Bedri, R, Coll Technol Hail, POB 1690, Hail, Saudi Arabia. EM r_bedri@yahoo.com CR 2002, ANSYS 2002 C PITTSB *ANSYS, 1999, US MAN REV 5 6 ATTABA M, 2002, ANSYS 2002 C PITTSB BATHE KJ, 1982, FINITE ELEMENT PROCE BOROVKOV AI, 2002, ANSYS 2002 C PITTSB CHEUNG YK, 1979, PRACTICAL INTRO FINI HUTCHINSON JR, 1967, J ACOUST SOC AM, V42, P398 LANCZOS C, 1964, VARIATIONAL PRINCIPL LIEPINS AA, 1965, AIAA J, V3, P1924 MEIROVITCH L, 1975, ELEMENTS VIBRATIONAL ODEN JT, 1976, VARIATIONAL METHODS RAO SS, 1982, FINITE ELEMENT METHO REDDY JN, 1984, ENERGY VARIATIONAL M REDDY JN, 1984, INTRO FINITE ELEMENT REDDY JN, 1985, APPL FUNCTIONAL ANAL SANDHU RS, 1971, INT J SOLIDS STRUCT, V7, P639 WANG E, 2002, ANSYS 2002 C PITTSB ZIENKIEWICZ OC, 1989, FINITE ELEMENT METHO NR 18 TC 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 J9 LECT NOTE COMPUT SCI PY 2005 VL 3401 BP 171 EP 178 PG 8 SC Computer Science, Theory & Methods GA BCF32 UT ISI:000229020800019 ER PT J AU Christophel, JR Couch, E Thole, KA Cunha, FJ TI Measured adiabatic effectiveness and heat transfer for blowing from the tip of a turbine blade SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article ID FLOW; LEAKAGE; MOTION AB The clearance gap between the tip of a turbine blade and the shroud has an inherent leakage flow from the pressure side to the suction side of the blade. This leakage flow of combustion gas and air mixtures leads to severe heat transfer rates on the blade tip of the high-pressure turbine. As the thermal load to the blade increases, blade alloy oxidation and erosion rates increase thereby adversely affecting component life. The subject of this paper is the cooling effectiveness levels and heat transfer coefficients that result from blowing through two holes placed in the forward region of a blade tip. These holes are referred to as dirt purge holes and are generally required for manufacturing purposes and expelling dirt from the coolant flow when operating in sandy environments. Experiments were performed in a linear blade cascade for two tip-gap heights over a range of blowing ratios. Results indicated that the cooling effectiveness was highly dependent on the tip-gap clearance with better cooling achieved at smaller clearances. Also, heat transfer was found to increase with blowing. In considering an overall benefit of cooling from the dirt purge blowing, a large benefit was realized for a smaller tip gap as compared with a larger tip gap. C1 Virginia Polytech Inst & State Univ, Dept Engn Mech, Blacksburg, VA 24061 USA. United Technol Corp, Pratt & Whitney Aircraft Co, E Hartford, CT 06108 USA. RP Christophel, JR, Virginia Polytech Inst & State Univ, Dept Engn Mech, Blacksburg, VA 24061 USA. CR ACHARYA S, 2002, GT200230553 ASME BINDON JP, 1989, ASME, V111, P257 BUNKER RS, 2000, ASME, V122, P263 CHYU MK, 1989, ASME, V111, P131 GNIELINSKI V, 1976, INT CHEM ENG, V16, P359 HOHLFELD EH, 2003, THESIS VIRGINIA POLY HOHLFELD EM, 2003, GT200338251 ASME JIN P, 2003, INT J ROTATING MACH, V9, P981 KAKAC S, 1987, HDB SINGLE PHASE CON, P34 KAYS WM, 1980, CONVECTIVE HEAT MASS, P269 KIM YW, 1995, J TURBOMACH, V117, P1 KIM YW, 1995, J TURBOMACH, V117, P12 KWAK JS, 2002, GT200230194 ASME KWAK JS, 2002, GT200230555 ASME LATTIME SB, 2002, 2002211794 NASA TM MAYLE RE, 1982, P 7 INT HEAT TRANSF, V3, P87 MOFFAT RJ, 1988, EXPT THERMAL FLUID S, V1, P3 MORPHIS G, 1988, 88GT256 ASME SEN B, 1994, 94GT311 ASME SRINIVASAN V, 2003, J TURBOMACH, V125, P267, DOI 10.1115/1.1554411 TALLMAN J, 2001, J TURBOMACH, V123, P324 YARAS MI, 1992, J TURBOMACH, V114, P652 NR 22 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD APR PY 2005 VL 127 IS 2 BP 251 EP 262 PG 12 SC Engineering, Mechanical GA 932BG UT ISI:000229528600002 ER PT J AU Meher-Homji, CB Prisell, E TI Dr. Max Bentele - Pioneer of the jet age SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Biographical-Item AB This paper documents the pioneering work of Dr. Max Bentele during his long and distinguished career in Germany, the UK, and the United States. His early work on turbojets at the Heinkel-Hirth Corporation in conjunction with his life-long friend, Dr. Hans von Ohain, culminated in the development of the advanced HeS 011 turbojet. Dr Bentele pioneering work in the area of blade vibration is documented along with details of his spectacular solution of the turbine blade vibration problem of the Junkers 004B engine which propelled the world's first operational jet fighter - the Me-262. Also covered are his pioneering contributions to turbine blade cooling and blade manufacturing and his important work at Curtiss-Wright and Avco Lycoming prior to his retirement. C1 Bechtel Corp, Turbomachinery Grp, Houston, TX 77056 USA. RP Meher-Homji, CB, Bechtel Corp, Turbomachinery Grp, 3000 Post Oak Blvd, Houston, TX 77056 USA. CR BENTELE M, PUBLICATION LIST NR 1 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 2005 VL 127 IS 2 BP 231 EP 239 PG 9 SC Engineering, Mechanical GA 926YZ UT ISI:000229160900002 ER PT J AU Kong, C Bang, J Sugiyama, Y TI Structural investigation of composite wind turbine blade considering various load cases and fatigue life SO ENERGY LA English DT Article AB This study proposes a structural design for developing a medium scale composite wind turbine blade made of E-glass/epoxy for a 750 kW class horizontal axis wind turbine system. The design loads were determined from various load cases specified at the IEC61400-1 international specification and GL regulations for the wind energy conversion system. A specific composite structure configuration, which can effectively endure various loads such as aerodynamic loads and loads due to accumulation of ice, hygro-thermal and mechanical loads, was proposed. To evaluate the proposed composite wind turbine blade, structural analysis was performed by using the finite element method. Parametric studies were carried out to determine an acceptable blade structural design, and the most dominant design parameters were confirmed. In this study, the proposed blade structure was confirmed to be safe and stable under various load conditions, including the extreme load conditions. Moreover, the blade adapted a new blade root joint with insert bolts, and its safety was verified at design loads including fatigue loads. The fatigue life of a blade that has to endure for more than 20 years was estimated by using the well-known S-N linear damage theory, the service load spectrum, and the Spera's empirical equations. With the results obtained from all the structural design and analysis, prototype composite blades were manufactured. A specific construction process including the lay-up molding method was applied to manufacturing blades. Full-scale static structural test was performed with the simulated aerodynamic loads. From the experimental results, it was found that the designed blade had structural integrity. In addition, the measured results of deflections, strains, mass, and radial center of gravity agreed well with the analytical results. The prototype blade was successfully certified by an international certification institute, GL (Germanisher Lloyd) in Germany. (c) 2004 Elsevier Ltd. All rights reserved. C1 Chosun Univ, Div Aerosp & Naval Architectural Engn, Kwangju, South Korea. Univ Osaka Prefecture, Dept Aerosp Engn, Sakai, Osaka, Japan. RP Kong, C, Chosun Univ, Div Aerosp & Naval Architectural Engn, Kwangju, South Korea. EM cdgong@mail.chosun.ac.kr CR 1994, IEC INT STANDARD 2000, 14001 IEC GL *EMRC, 1992, NISAII USERS MANUAL ACKERMANN T, 2000, RENEW SUST ENERG REV, V4, P315 BECHLY ME, 1997, COMPUT STRUCT, V63, P639 BISHOP NWM, 1991, FATIGUE ANAL WIND TU BROEK D, 1982, ELEMENTARY ENG FRACT DELFT DRV, 1991, FULL SCALE FATIGUE T GOURIERES DLE, 1982, WIND POWER PLANTS TH INOMATA N, 1999, RENEW ENERG, V16, P912 KIM JS, 2000, RENEWABLE ENERGY DEV KONG C, 1999, J KSPE, V3, P40 KONG C, 2000, J KSPE, V4, P22 KONG C, 2000, J KSPE, V4, P29 KONG C, 2000, KSAS INT J, V1, P92 KONG C, 2000, P 3 AS PAC C AER TEC, P376 KONG C, 2000, STUDY STRUCTURAL AER KONG C, 2001, 13 INT C COMP MAT IC LLOYD G, 1999, REGULATIONS CERTIFIC MANDELL JF, 1992, SAND92S7005 MAYER RM, 1996, DESIGN COMPOSITE STR, P195 MINER MA, 1945, J APPL MECH, V12, P159 PALMGREN A, 1924, Z VER DTSCH ING, V68, P339 SPERA DA, 1993, WINDPOWER 93, P282 VEERS PS, 1993, WINDPOWER 93, P342 ZWEBEN C, 1989, MECH BEHAV PROPERTIE, V1 NR 26 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD AUG-SEP PY 2005 VL 30 IS 11-12 SI Sp. Iss. SI BP 2101 EP 2114 PG 14 SC Thermodynamics; Energy & Fuels GA 928LJ UT ISI:000229272800007 ER PT J AU Muwanga, RS Sreekanth, S Grigore, D Trindade, R Lucas, T TI Effect of input variability on the performance of turbine blade thermal design using Monte Carlo simulation: An exploratory study SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article AB A probabilistic approach to the thermal design and analysis of cooled turbine blades is presented. Various factors that affect the probabilistic performance of the blade thermal design are grouped into categories and a select number of factors known to be significant, for which the variability could be assessed are modeled as random variables. The variability data for these random variables were generated from separate Monte Carlo simulations (MCS) of the combustor and the upstream stator and secondary air system. The oxidation life of the blade is used as a measure to evaluate the thermal design as well as to evaluate validity of the methods. Two approaches have been explored to simulate blade row life variability and compare it with the field data. Field data from several engine removals are used for investigating the approach. Additionally a response surface approximation technique has been explored to expedite the simulation process. The results indicate that the conventional approach of a worst-case analysis is overly conservative and analysis based on nominal values could be very optimistic. The potential of a probabilistic approach in predicting the actual variability of the blade row life is clearly evident in the results. However, the results show that, in order to predict the blade row life variability adequately, it is important to model the operating condition variability. The probabilistic techniques such as MCS could become very practical when approximation techniques such as response surface modeling are used to represent the analytical model. C1 Pratt & Whitney Canada, Turbine Module Ctr, Mississauga, ON L5T 1J3, Canada. Concordia Univ, Dept Mech & Ind Engn, Montreal, PQ H3G 1M8, Canada. Pratt & Whitney Canada, Prod Reliabil & Safety, Longueuil, PQ J4G 1A1, Canada. Pratt & Whitney Canada, Turbine Module Ctr, Longueuil, PQ J4G 1A1, Canada. RP Sreekanth, S, Pratt & Whitney Canada, Turbine Module Ctr, 1801 Courtney Pk Dr, Mississauga, ON L5T 1J3, Canada. EM roland.muwanga@pwc.ca sri.sreekanth@pwc.ca daniel.grigore@pwc.ca ricardo.trindade@pw.utc.com terry.lucas@pwc.ca CR *ENG SOFTW INC, 2001, ISIGHT REF GUID, P271 CHIOCEL DM, 1999, P 1999 AIAA ASME ASC, V4, P2980 DAILEY D, 2000, VKI LECT SERIES 0228, V2000 GARZON VE, 2003, J TURBOMACH, V125, P692, DOI 10.1115/1.1622715 LIU J, 2002, MED RES REV, V22, P1 LYKINS C, 1994, P 35 AIAA ASME ASCE, P1069 POMFRET C, 1995, AEROSPACE ENG, V15, P9 SHEN MHH, 1999, INT J FATIGUE, V21, P699 SIDWELL V, 2003, P ASME TURB EXP 2003, P10 NR 9 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANSFER JI J. Heat Transf.-Trans. ASME PD APR PY 2005 VL 127 IS 4 BP 404 EP 413 PG 10 SC Thermodynamics; Engineering, Mechanical GA 921HJ UT ISI:000228754600007 ER PT J AU Song, JX Han, YF Li, SS Xiao, CB TI Repair of NiCrAlYSi overlay coating on Ni3Al base alloy IC6 SO INTERMETALLICS LA English DT Article DE nickel aluminides, based on Ni3Al; mechanical properties at high temperatures; mechanical properties at ambient temperature; coatings; microstructure ID TURBINE-BLADES AB The effect of repair of NiCrAlYSi coating after long time use on the coherence of coating to substrate and mechanical properties of Ni3Al base alloy IC6 has been studied. The alloy with NiCrAlYSi coating was stressed under the condition of 900 degrees C/100 MPa for 200 h to simulate the service condition of IC6 turbine vanes. The results showed that the coherence of base alloy/original coating, original coating/first repair coating, first repair coating/second repair coating or base alloy/second repair coating was firm. The interfaces between them had no cracks and porosity, for either partly or entirely repaired coatings. However, there were more Mo rich particles in the affected zone compared with original coating. Compared with IC6 alloy aged at 900 degrees C for 200 h, the yield strength at ambient temperature of IC6 alloy with first repair coating was almost equivalent. while the elongation decreased slightly; its stress rupture life under 1100 degrees C/90 MPa condition was about 100 h. For secondary coating repair, the room temperature tensile properties of base alloy had no obvious change, while stress rupture lives decreased, but still were rather long, compared to the alloy with first repair coating. Therefore, NiCrAlYSi coating repair,is feasible to prolong the service lives of IC6 turbine vanes. (c) 2004 Elsevier Ltd. All rights reserved. C1 Beijing Inst Aeronaut Mat, Natl Key Lab Adv High Temperature Struct Mat, Beijing 100095, Peoples R China. Beijing Univ Aeronaut & Astronaut, Sch Mat, Beijing 100083, Peoples R China. RP Song, JX, Beijing Inst Aeronaut Mat, Natl Key Lab Adv High Temperature Struct Mat, Beijing 100095, Peoples R China. EM songjx@vip.sina.com CR BEDDOES JC, 1980, METALLOGRAPHY, V13, P185 HAN YF, 1993, MAT SCI ENG A-STRUCT, V160, P271 HAN YF, 1995, MAT SCI ENG A-STRUCT, V192, P899 HAN YF, 1997, MAT SCI ENG A-STRUCT, V239, P871 HAN YF, 1997, STRUCTURAL INTERMETA, P713 HAN YF, 2000, MAT ENG, V5 HUO X, 1999, SURF COAT TECH, V114, P174 KOUL AK, 1988, METALL TRANS A, V19, P2049 LVOVA E, 2001, J MATER ENG PERFORM, V10, P299 SONG JX, 2002, ACTA METALL SIN, V38, P250 WANG B, 2001, OXID MET, V56, P1 WEN L, 2001, P 4 PAC RIM INT C AD, P2715 NR 12 TC 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD MAR-APR PY 2005 VL 13 IS 3-4 SI Sp. Iss. SI BP 351 EP 355 PG 5 SC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 906UC UT ISI:000227668000019 ER PT J AU Dhar, D Sharan, AM Rao, JS TI Transient stress analysis and fatigue life estimation of turbine blades SO JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME LA English DT Article AB This paper is concerned with life estimation of a turbine blade taking into account the combined effects of centrifugal stresses, vibratory stresses and thermal stresses. The stresses are determined by accounting for the rotor acceleration. The blades are subjected to aerodynamic excitation force obtained from thin cambered aerofoil theory tinder in compressible flow. The thermo-elastic forces are obtained from the three-dimensional non-linear heat transfer equations using the finite element analysis. The fatigue life is estimated using two well known theories, from the number of cycles in various blocks during start-up and shut-down periods of the turbine operation when the stresses peak. C1 Mem Univ Newfoundland, Fac Engn & Appl Sci, St Johns, NF A1B 3X5, Canada. IIT, Dept Mech Engn, New Delhi, India. RP Dhar, D, Mem Univ Newfoundland, Fac Engn & Appl Sci, St Johns, NF A1B 3X5, Canada. CR BAGCI C, 1981, MECH MACH THEORY, V16, P339 BAHREE R, 1987, THESIS MEMORIAL U NE BAHREE R, 1989, ASME J ENG GAS TURBI, V3, P618 COLLINS JA, 1981, FAILURE MAT MECH DES COOK RD, 1981, CONCEPTS APPL FINITE, P13 CUBBERLY WH, 1980, ASM METALS REFERENCE, V3, P248 DHAR D, 1994, THESIS MEMORIAL U NE GUPTA K, 1979, THESIS LIT DELH DELH, CH6 HEYWOOD RB, 1962, DESIGNING AGAINST FA IRRTIER H, 1986, P IFTOMM INT C ROTO, P301 LITTLER DJ, 1969, P INT C HELD BERK CA, P374 MARCO SM, 1954, T ASME, V76, P627 MEIROVITCH L, 1975, ELEMENTS VIBRATION A, P143 OSGOOD CC, 1982, FATIGUE DESIGN RAO JS, 1987, P 7 WORLD C IFTOMM, P697 RAO JS, 1991, TURBOMACHIEN BLADE V RAO JS, 1991, TURBOMACHINE BLADE V RAO JS, 1994, TURBMACHINE UNSTEADY RAO JS, 1999, 99GT287 ASME RAO JS, 2000, TURBINE BLADE LIFE E RUST T, 1982, P EPRI WORKSH STEAM SEGERLIND LJ, 1984, APPL FINITE ELEMENT, P177 TURPIN A, 1994, ASME J ENG GAS TURBI, V116, P718 VYAS NS, 1986, THESIS IIT DELHI, V116, P718 VYAS NS, 1994, J ENG GAS TURB POWER, V116, P198 WARIKOO R, 1992, MARINE STRUCT, V5, P255 WEAST RC, 1975, HDB CHEM PHYS ZIENKIEWICZ OC, 1977, FINITE ELEMENT METHO, P169 NR 28 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1048-9002 J9 J VIB ACOUST JI J. Vib. Acoust.-Trans. ASME PD OCT PY 2004 VL 126 IS 4 BP 485 EP 495 PG 11 SC Acoustics; Engineering, Mechanical; Mechanics GA 890AZ UT ISI:000226485400003 ER PT J AU Sutherland, HJ Mandell, JF TI The effect of mean stress on damage predictions for spectral loading of fibreglass composite coupons SO WIND ENERGY LA English DT Article DE wind; blades; fatigue; spectral; fibreglass ID LIFE PREDICTION; FATIGUE; MODEL AB In many analyses of wind turbine blades the effects of mean stress on the determination of damage in composite blades are either ignored completely or characterized inadequately. Mandell et al. have recently presented an updated Goodman diagram for a fibreglass material that is typical of the materials used in wind turbine blades. Their formulation uses the MSU/DOE fatigue database to develop a Goodman diagram with detailed information at 13 R-values. Using these data, linear, bilinear and full Goodman diagrams are constructed using mean and '95/95' fits to the data. The various Goodman diagrams are used to predict the failure stress for coupons tested using the WISPERX spectrum. Three models are used in the analyses. The first is the linear Miner's rule commonly used by the wind industry to predict failure (service lifetimes). The second is a non-linear variation of Miner's rule which computes a non-linear Miner's residual strength based upon an exponential degradation parameter. The third is a generalized non-linear residual strength model that also relies on an exponential degradation parameter. The results illustrate that Miner's rule does not predict failure very well. When the mean full Goodman diagram is used, the non-linear models predict failures near the mean of the experimental data, and when the 95/95 Goodman diagram is used, they predict the lower bound of the measured data very well. (C) Published in 2004 by John Wiley Sons, Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Montana State Univ, Bozeman, MT 59717 USA. RP Sutherland, HJ, Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM hjsuthe@sandia.gov CR *ASTM, 1991, E73991 ASTM EPAARACHCHI JA, 2003, COMPOS PART A-APPL S, V34, P313, DOI 10.1016/S1359-835X(03)00052-6 HWANG W, 1986, J COMPOS MATER, V20, P125 KENSCHE CW, 1996, DESIGN COMPOSITE STR, P65 MANDELL JF, 1997, SAND973002 SAND NAT MANDELL JF, 1998, NRELSR50024374 MANDELL JF, 2002, SAND2002077 SAND NAT MANDELL JF, 2003, ICCM14 SMEASC NIJSSEN RPL, 2002, 2002 ASME WIND EN S, P10 RONOLD KO, 1996, COMPOS PART A-APPL S, V27, P485 SCHAFF JR, 1997, J COMPOS MATER, V31, P158 SENDECKYJ GP, 1991, FATIGUE COMPOSITE MA, P431 SUTHERLAND HJ, 2000, 2000 ASME WIND EN S, P413 SUTHERLAND HJ, 2004, 2004 ASME WIND EN S TENHAVE AA, 1992, NLRTP91476U WAHL NK, 2002, SAND20020546 SAND NA YANG JN, 1990, J COMPOS MATER, V24, P753 NR 17 TC 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1095-4244 J9 WIND ENERGY JI Wind Energy PD JAN-MAR PY 2005 VL 8 IS 1 BP 93 EP 108 PG 16 SC Energy & Fuels; Engineering, Mechanical GA 885IA UT ISI:000226149100008 ER PT J AU Lund, E Stegmann, J TI On structural optimization of composite shell structures using a discrete constitutive parametrization SO WIND ENERGY LA English DT Article DE innovative concepts; structural optimization; laminated composites; design of composites ID DESIGN; PLATES AB In this article a novel method for structural optimization of laminated composite shell structures such as wind turbine blades is presented. The outer shape of a wind turbine blade is typically determined by aerodynamic considerations and therefore not subject to change. Furthermore, the thicknesses of the shell structures are also considered fixed. The design objective is chosen to be a global quantity such as maximum stiffness or lowest eigenfrequency with a constraint on the total mass, such that the cost of material can be considered The design optimization method is based on ideas from multiphase topology optimization where the material stiffness (or density) is computed as a weighted sum of candidate materials, and the method is easy to implement in existing finite element codes. The potential of the method to solve the combinatorial problem of proper choice of material, stacking sequence and fibre orientation simultaneously for maximum stiffness or lowest eigenfrequency design is illustrated on both small test examples and a real-life main spar from a wind turbine blade. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Univ Aalborg, Inst Engn Mech, DK-9220 Aalborg E, Denmark. RP Lund, E, Univ Aalborg, Inst Engn Mech, Pontoppidanstr 101, DK-9220 Aalborg E, Denmark. EM el@ime.aau.dk CR AHMAD S, 1970, INT J NUMER METH ENG, V2, P419 BATHE KJ, 1996, FINIRE ELEMENT PROCE BENDSOE MP, 1983, J STRUCT MECH, V11, P523 BENDSOE MP, 2003, TOPOLOGY OPTIMIZATIO BRUYNEEL M, 2002, ADV ENG SOFTW, V33, P697 CHENG KT, 1981, INT J SOLIDS STRUCT, V17, P305 COURANT R, 1953, METHODS MATH PHYSIS, V1 DVORKIN EN, 1984, ENG COMPUT, V1, P77 FOLDAGER JP, 2001, STRUCT MULTIDISCIP O, V21, P14 GIBIANSKY LV, 2000, J MECH PHYS SOLIDS, V48, P461 GURDAL Z, 1999, DESIGN OPTIMIZATION LUND E, 1994, THESIS AALB U MASUR EF, 1970, J ENG MECH DIVISION, V96, P621 MIKI M, 1993, AIAA J, V31, P921 MOITA JS, 2000, COMPUT STRUCT, V79, P407 PEDERSEN P, 1991, STRUCT OPTIMIZATION, V3, P69 PEDERSEN P, 2000, STRUCT MULTIDISCIP O, V19, P169 PRAGER W, 1970, J OPTIMIZATION THEOR, V6, P1 SEYRANIAN AP, 1994, STRUCT OPTIMIZATION, V8, P207 SIGMUND O, 1997, J MECH PHYS SOLIDS, V45, P1037 STEGMANN J, 2003, P 5 WORLD C STRUCT M STEGMANN J, 2003, P AM SOC COMP 18 TEC STEGMANN J, 2004, INT J NUMERICAL METH SVANBERG K, 1987, INT J NUMER METH ENG, V24, P359 TSAI SW, 1968, COMPOSITE MAT WORKSH, P233 WITTRICK WH, 1962, J ROYAL AERONAUTICAL, V66, P590 NR 26 TC 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1095-4244 J9 WIND ENERGY JI Wind Energy PD JAN-MAR PY 2005 VL 8 IS 1 BP 109 EP 124 PG 16 SC Energy & Fuels; Engineering, Mechanical GA 885IA UT ISI:000226149100009 ER PT J AU Dungey, C Bowen, P TI The effect of combined cycle fatigue upon the fatigue performance of TI-6AL-4V fan blade material SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article DE combined high and low cycle fatigue; Ti-6Al-4V AB Samples of Ti-6Al-4V (wt.%) were tested to failure under low cycle fatigue (LCF), high cycle fatigue (HCF), and combined cycle fatigue (CCF), respectively, in order to ascertain the effects of the combined cycle situation upon the total fatigue life. The results indicate that the effect of the combined loading is variable and dependent upon the conditions during testing. It has been found that the application of CCF is detrimental to fatigue life under conditions of large vibrational amplitudes characterised by a stress ratio of 0.2, which becomes increasingly significant at the lower overall maximum stress conditions employed. Conversely an increase in total fatigue life was, however observed for constant mean stress (550 MPa) testing when the overall vibrational amplitude and total stress range approached that of the applied mean stress. The CCF loading block employed simulated two basic features of a typical gas turbine engine flight pattern. A major stress cycle represented start-stop operations, which give rise to low cycle fatigue. In-flight vibrations, which could give rise to, HCF were represented by superimposed minor cycles of high frequency upon the dwell portion of the major stress profile. This combined loading pattern was applied in a specially developed facility, consisting of two computer controlled axially aligned servo-hydraulic actuators. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Birmingham, Dept Met & Mat, Birmingham B15 2TT, W Midlands, England. RP Dungey, C, Univ Birmingham, Dept Met & Mat, Birmingham B15 2TT, W Midlands, England. EM cxd692@bham.ac.uk CR BOYCE BL, 2001, ENG FRACT MECH, V68, P129 COWLES BA, 1996, INT J FRACTURE, V80, P147 FLECK NA, 1984, 6 INT C FRACT DELH, P1832 NR 3 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECHNOL JI J. Mater. Process. Technol. PD NOV 10 PY 2004 VL 153-54 PN Part 1 Sp. Iss. SI BP 374 EP 379 PG 6 SC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary GA 881EF UT ISI:000225845500059 ER PT J AU Riziotis, VA Voutsinas, SG Politis, ES Chaviaropoulos, PK TI Aeroelastic stability of wind turbines: the problem, the methods and the issues SO WIND ENERGY LA English DT Article DE aeroelastic stability; wind turbines; dynamic stall models; multiblade transformation ID VISCEL PROJECT; DYNAMIC STALL; BLADES AB Aeroelastic stability is a key issue in the design process of wind turbines towards both enchanced stability and increased fatigue life. The theory and models behind the state-of-the-art aeroelastic stability tools developed for the analysis of the complete wind turbine at the Centre for Renewable Energy Sources and the National Technical University of Athens are presented in this article. Application examples of stability calculations for a pitch, variable speed and a stall-regulated wind turbine ore also presented. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Ctr Renewable Energy Sources, GR-19009 Pikermi, Greece. Natl Tech Univ Athens, Dept Mech Engn, GR-15780 Athens, Greece. RP Politis, ES, Ctr Renewable Energy Sources, 19th Km Marathonos Ave, GR-19009 Pikermi, Greece. EM vpolitis@cres.gr CR BERTAGNOLIO F, 2003, P 2003 EUR WIND EN C CHAVIAROPOULOS P, 2003, P 2003 EUR WIND EN C CHAVIAROPOULOS PK, 1999, WIND ENERGY, V2, P99 CHAVIAROPOULOS PK, 2001, WIND ENERGY, V4, P183 CHAVIAROPOULOS PK, 2003, WIND ENERGY, V6, P365, DOI 10.1002/we.100 CHAVIAROPOULOS PK, 2003, WIND ENERGY, V6, P387, DOI 10.1002/we.101 EGGLESTON DE, 1987, WIND TURBINE ENG DES FUGLSANG P, 2003, P 2003 EUR WIND EN C HANSEN MH, 2003, RISOR1354EN RIS NAT HANSEN MH, 2003, WIND ENERGY, V6, P179, DOI 10.1002/we.79 HANSEN MH, 2004, WIND ENERGY, V7, P133, DOI 10.1002/we.116 HIBBS B, 1983, HORIZONTAL AXIS WIND JOHNSON W, 1980, HELICOPTER THEORY KIRCHGASSNER B, 1984, P 1994 EUR WIND EN C, P22 LINDENBURG C, 2003, P 2003 EUR WIND EN C PETERSEN JT, 1998, RISOR1045EN RIS NAT PETOT D, 1989, RECH AEROSPATIALE, P59 RASMUSSEN F, 1999, J SOL ENERG-T ASME, V121, P150 RIZIOTIS VA, 1997, P 1997 EUR WIND EN C, P448 THOMSEN K, 2000, WIND ENERGY, V3, P233 NR 20 TC 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1095-4244 J9 WIND ENERGY JI Wind Energy PD OCT-DEC PY 2004 VL 7 IS 4 BP 373 EP 392 PG 20 SC Energy & Fuels; Engineering, Mechanical GA 878HC UT ISI:000225636400009 ER PT J AU Wright, AD Balas, MJ TI Design of controls to attenuate loads in the controls advanced research turbine SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The wind industry seeks to design wind turbines to maximize energy production and increase fatigue life. To achieve this goal, we must design wind turbines to extract maximum energy and reduce component and system loads. This paper applies modern state-space control design methods to a two-bladed teetering-hub upwind machine located at the National Wind Technology Center The design objective is to regulate turbine speed in region 3 (above rated wind speed) and enhance damping in several low-damped flexible modes of the turbine. The controls approach is based on the Disturbance Accommodating Control method and provides accountability for wind-speed disturbances. First, controls are designed with the single control input rotor collective pitch. to stabilize the first drive-train torsion as well as the tower first fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances first drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections caused by wind shear. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wright, AD, Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM Alan_wright@nrel.gov Mark.balas@colorado.edu CR BALAS MJ, 1980, J INTERDISCIPLINARY, P63 BALAS MJ, 1990, SPIE CONT ORLANDO BALAS MJ, 1998, P 1998 ASME WIND EN, P95 BARTON RS, 1979, CONTROL STABILAZATIO, P325 BOSSANYI EA, 2000, P 2000 ASME WIND EN, P64 HINRICHSEN EN, 1984, IEEE T POWER AP SYST, V103, P886 JOHNSON CD, 1976, CONTROL DYNAMIC SYST, V12, P387 JONKMAN JM, 2004, NRELEL50029798 NAT R LIEBST BS, 1983, J ENERGY, V7, P182 MATTSON SE, 1984, THESIS LUND I TECHNO STOL K, 2000, P 19 ASME WIND EN S, P84 STOL K, 2001, THESIS U COLARADO STOL K, 2002, P 21 AIAA ASME WIND, P310 WRIGHT AD, 2002, P 2002 ASME WIND EN WRIGHT AD, 2003, P 22 ASME WIND EN S, P304 WRIGHT AD, 2003, THESIS U COLARADO NR 16 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2004 VL 126 IS 4 BP 1083 EP 1091 PG 9 SC Energy & Fuels; Engineering, Mechanical GA 876BP UT ISI:000225470900015 ER PT J AU Tschiptschin, AP Azevedo, CRF TI Failure analysis of turbo-blower blades SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE power-plant failures; turbine blade failures; corrosion-fatigue; stainless steel; pitting corrosion AB Twelve percent chromium martensitic stainless steel blades of the medium-pressure stage of a thermoelectric centre turbo-blower broke during use. The present work will investigate the possible causes for the premature failure of these blades and the condition of the high-pressure blades. The results indicated that at least one of the blades of the medium-pressure stage failed by a corrosion-fatigue mechanism, whose nucleation was associated with the presence of corrosion pits on its suction side. The high-pressure blades presented hardness bellow the specification and presence of corrosion pits and cracks. The softening of the microstructure (from 250 to 220 HV) could not be explained by microstructural instability during the intermittent use of the blade, indicating that either the material was initially tempered at a higher temperature or that the working temperature is higher than the predicted. A rough and conservative estimation of the residual life of the high-pressure blades indicated that the high-pressure blades should also replaced. The quality of the feed water (from the sea) used for the production of the vapour should be optimised and any action taken to improve the cleanliness and dryness of the equipment during its intermittent use may improve the life of the blades. (C) 2004 Elsevier Ltd. All rights reserved. C1 Inst Pesquisas Tecnol Estado Sao Paulo SA, Lab Met & Failure Anal, BR-01064970 Sao Paulo, Brazil. Univ Sao Paulo, Escola Politecn, Dept Mat & Met Engn, BR-05508900 Sao Paulo, SP, Brazil. RP Azevedo, CRF, Inst Pesquisas Tecnol Estado Sao Paulo SA, Lab Met & Failure Anal, POB 0141, BR-01064970 Sao Paulo, Brazil. EM crfaze@ipt.br CR 1990, ASM METALS HDB PROPE, V1, P941 *US DEP INT, FAC INSTR STAND TECH, V2 COX WM, 1987, METALS HDB, V13, P1001 CRUZ RPV, 1998, CORROS SCI, V40, P125 DAS G, 2003, ENG FAIL ANAL, V10, P85 ISHII H, 1982, METALL T A, V13, P1521 KERLINS V, 1987, ASM HDB FRACTOGRAPHY, V12, P35 MEETHAM GW, 1981, DEV GAS TURBIN MAT, P261 PICKERING FB, 1979, METALLURGICAL EVOLUT, P47 TROSHCHENKO VT, 2000, ENG FAIL ANAL, V7, P209 VISWANATHAN R, 1987, METALS HDB, V13, P999 NR 11 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD FEB PY 2005 VL 12 IS 1 BP 49 EP 59 PG 11 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 876XQ UT ISI:000225532500006 ER PT J AU Van Paepegem, W Degrieck, J TI Simulating in-plane fatigue damage in woven glass fibre-reinforced composites subject to fully reversed cyclic loading SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE composites; fatigue; residual stiffness; tension-compression ID RESIDUAL STIFFNESS; LIFE PREDICTION; BENDING FATIGUE; MECHANICS; STRENGTH AB The interest in using fibre-reinforced composites in structural components is increasing. Some of these structural composites, such as wind turbine blades, aircraft components and torsion shafts are subject to fatigue loadings. It is widely accepted that fully reversed cyclic loading is the most adverse loading for fibre-reinforced composites, but the modelling of the material behaviour under this loading condition is very difficult. In this paper, a damage model is presented for woven glass fibre-reinforced composites subject to fully reversed cyclic loading. First fatigue experiments have been conducted in displacement-controlled fully reversed bending and the stiffness degradation and damage patterns have been observed. Based on these experimental data, a damage model has been developed, which includes the in-plane stress components and the degradation of the in-plane elastic properties. The model has been implemented in a commercial finite-element code and simulation of the successive stages in the fatigue life has been performed. The model has been validated for a plain woven glass fabric reinforced composite and simulated stiffness degradation, damage growth and damage distribution have been compared with experimental data. C1 Ghent Univ, Dept Mech Construct & Prod, B-9000 Ghent, Belgium. RP Van Paepegem, W, Ghent Univ, Dept Mech Construct & Prod, St Pietersnieuwstr 41, B-9000 Ghent, Belgium. EM wim.vanpaepegem@ugent.be CR ADAM T, 1994, INT J FATIGUE, V16, P533 BADALIANCE R, 1982, ASTM STP, V787, P274 BARTLEYCHO J, 1998, COMPOS SCI TECHNOL, V58, P1535 CHABOCHE JL, 1988, J APPL MECH, V55, P59 CHABOCHE JL, 1988, J APPL MECH, V55, P65 CHEN AS, 1993, ICCM 9 COMPOSITES PR, V4, P899 CURTIS PT, 1989, ADV POLYM COMPOSITES, P331 FERRY L, 1997, P INT C FAT COMP 3 5, P266 FUJII T, 1993, COMPOS SCI TECHNOL, V49, P327 GAMSTEDT EK, 1999, COMPOS SCI TECHNOL, V59, P167 GATHERCOLE N, 1994, INT J FATIGUE, V16, P523 HANSEN U, 1997, P 18 RIS INT S MAT S, P345 HERRINGTON PD, 1992, J COMPOS MATER, V26, P2045 HIGHSMITH AL, 1982, ASTM STP, V775, P103 KACHANOV LM, 1958, IZV AKAD NAUK USS TN, V8, P26 KACHANOV LM, 1986, INTRO CONTINUUM DAMA, P135 KRAJCINOVIC D, 1985, J APPL MECH-T ASME, V52, P829 KRAJCINOVIC D, 1987, CONTINUUM DAMAGE MEC, P294 LEMAITRE J, 1971, UNPUB P ICM I KYOT OBRIEN TK, 1981, J COMPOS MATER, V15, P55 REIFSNIDER KL, 1987, P 6 INT C COMP MAT I, V4 SCHULTE K, 1987, P 6 INT C COMP MAT I, V4 SIDOROFF F, 1984, P EUROPEAN MECH C, V182, P21 VANPAEPEGEM W, 2002, COMPOS SCI TECHNOL, V62, P687 VANPAEPEGEM W, 2002, FATIGUE FRACT ENG M, V25, P547 VANPAEPEGEM W, 2002, INT J FATIGUE, V24, P747 VANPAEPEGEM W, 2002, THESIS GHENT U GENT, P403 VANPAEPEGEM W, 2003, COMPOS SCI TECHNOL, V63, P305 VANPAEPEGEM W, 2003, COMPOS SCI TECHNOL, V63, P677 NR 29 TC 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD DEC PY 2004 VL 27 IS 12 BP 1197 EP 1208 PG 12 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 873FH UT ISI:000225264800009 ER PT J AU Hughes, JI Sharman, ARC Ridgway, K TI The effect of tool edge preparation on tool life and workpiece surface integrity SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE LA English DT Article DE surface integrity; Ti-6Al-4V; titanium alloys; turning ID MACHINING TITANIUM-ALLOYS; CARBIDE TOOLS; MACHINABILITY; PERFORMANCE; TI-6AL-4V; GEOMETRY; FINISH; STEEL AB Titanium alloys are classified as 'hard to machine' due to their intrinsic properties of low thermal conductivity, low modulus of elasticity, high strength at elevated temperatures and high chemical affinity with all available cutting tool materials. The alpha-beta alloy Ti-6Al-4V is the most common alloy and is used extensively in the aerospace industry for structural components and as compressor blades, discs, casings, etc., in the cooler parts of gas turbine engines. It is critical to industries such as the aerospace industry that the effects of operating parameters on surface integrity are known and understood before new tool geometries and strategies are accepted. There is extensive literature available detailing all aspects of the machinability of titanium alloys, which is briefly reviewed; however, little of this refers specifically to surface integrity. This paper focuses on the effects of cutting tool preparation, cutting speed and feed rate on tool wear/life with special emphasis on workpiece surface integrity. C1 Univ Sheffield, Adv Mfg Res Ctr Boeing, Dept Mech Engn, Sheffield S1 3JD, S Yorkshire, England. RP Sharman, ARC, Univ Sheffield, Adv Mfg Res Ctr Boeing, Dept Mech Engn, Sheffield S1 3JD, S Yorkshire, England. EM a.sharman@sheffield.ac.uk CR *ISO, 1993, 3685 ISO BHAUMIK SK, 1995, MATER DESIGN, V16, P221 BOYER R, 1994, MAT PROPERTIES HDB T BOYER RR, 1996, MAT SCI ENG A-STRUCT, V213, P103 CHEHARON CH, 2001, J MATER PROCESS TECH, V118, P231 COLWELL LV, 1954, MECH ENG, V76, P461 DEARNLEY PA, 1986, MATER SCI TECH SER, V2, P47 DEARNLEY PA, 1987, HIGH TECH CERAM, V38, P2699 DIACK MI, 1995, TITANIUM 95 SCI TECH, P763 DONACHIE MJ, 1988, TITANIUM TECHNICAL G DONACHIE MJ, 2002, SUPERALLOYS TECHNICA EZUGWU EO, 1997, J MATER PROCESS TECH, V68, P262 EZUGWU EO, 2003, J MATER PROCESS TECH, V134, P233 HARTUNG PD, 1982, ANN CIRP, V31, P75 JAWAID A, 1996, P 3 INT C PROGR CUTT, P126 JEELANI S, 1983, WEAR, V85, P121 JEELANI S, 1985, J MATER SCI, V20, P3245 KAHLES JF, 1985, J MET, V37, P27 KALPAKJIAN S, 1995, MANUFACTURING ENG TE KIM KW, 1999, J MATER PROCESS TECH, V86, P45 KISHAWY HA, 1999, INT J MACH TOOL MANU, V39, P1017 KOMANDURI R, 1982, WEAR, V76, P15 KOMANDURI R, 1983, WEAR, V92, P113 KOSTER WP, 1973, P N AM METALWORK RES, V2, P67 LEE M, 1981, P TIT PHYS MET COMM, P275 LOPEZDELACALLE LN, 2000, J MATER PROCESS TECH, V100, P1 MACHADO AR, 1990, P I MECH ENG B-J ENG, V204, P53 MACHADO AR, 1998, MACH SCI TECHNOL, V2, P1 MIN W, 1988, MAT SCI TECHNOL, V4, P548 MUNOZESCALONA P, 1998, WEAR, V218, P103 NABHANI F, 2001, ROBOT CIM-INT MANUF, V17, P99 NARUTAKI N, 1983, ANN CIRP, V32, P65 RIBEIRO MV, 2003, J MATER PROCESS TECH, V143, P458, DOI 10.1016/S0924-0136(03)00457-6 SMITH WF, 1993, STRUCTURE PROPERTIES THIELE JD, 1999, J MATER PROCESS TECH, V94, P216 WALTER JL, 1993, WEAR, V170, P79 WANG ZM, 1997, TRIBOL T, V40, P81 WANG ZY, 1996, T NAMRI SME, V24, P3 YANG XP, 1999, MACH SCI TECHNOL, V3, P107 ZLATIN N, 1973, TITANIUM SCI TECHNOL, V1, P489 NR 40 TC 1 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0954-4054 J9 PROC INST MECH ENG B-J ENG MA JI Proc. Inst. Mech. Eng. Part B-J. Eng. Manuf. PD SEP PY 2004 VL 218 IS 9 BP 1113 EP 1123 PG 11 SC Engineering, Manufacturing; Engineering, Mechanical GA 863PC UT ISI:000224573000009 ER PT J AU Stubbs, T TI The role of NDE in the life management of steam turbine rotors SO INSIGHT LA English DT Article AB The rotors of steam turbines are subject to life limitations due to creep and thermal fatigue. Creep occurs during steady-state operation due to the centrifugal stresses sustained at high temperature, while thermal fatigue arises front cyclic thermal stresses set tip during start-up and shut-down. The most serious threat to the safety of these rotors arises from the possibility that, near the bore, creep cracks may initiate and grow to a size which could result in a brittle fracture of the rotor during a cold start. Initiation may be assisted by any pre-existing forging defects in the near-bore region and growth may be assisted by fatigue due to the thermal and mechanical stresses applied during starting. Creep cracking can also occur at blade root fixings, leading eventually to the loss of blades and possibly substantial consequential damage to the turbine. Creep, thermal fatigue, and additionally stress corrosion cracking can occur at other stress-concentrating features such as of any balance holes and changes of section; the effect cracking at such features is dependant upon the local stress levels. The detection, classification and sizing of flaws is therefore critical to life extension of steam turbine rotors. CR MURPHY TF, GE POWER SYSTEMS GEN NR 1 TC 1 PU BRITISH INST NON-DESTRUCTIVE TESTING PI NORTHAMPTON PA 1 SPENCER PARADE, NORTHAMPTON NN1 5AA, NORTHANTS, ENGLAND SN 1354-2575 J9 INSIGHT JI Insight PD SEP PY 2004 VL 46 IS 9 BP 529 EP 532 PG 4 SC Instruments & Instrumentation; Materials Science, Characterization & Testing GA 852XH UT ISI:000223789600012 ER PT J AU Crowther, P TI Non-destructive evaluation of coatings for land-based gas turbines using a multi-frequency eddy current technique SO INSIGHT LA English DT Article AB To provide a commercial return from Combined Cycle Gas Turbine (CCGT) technology for power generation, a balance has to be struck between efficiency, maintenance costs and component life. The parts that significantly influence this are collectively known as Hot Gas Path (HGP) components and generally consist of blades, vanes and heat shields. To achieve high thermal efficiencies, these components are subject to high temperatures, centripetal forces and erosive/corrosive atmospheres and therefore need to be protected by complex coatings and through internal cooling. The drive for higher efficiencies, however, often means that the protection put in place is only a partial solution and experience shows that these components have a relatively short lifespan and require regular inspection. Inspections to date have consisted of visual examination and fluorescent penetrant inspections and, therefore, are limited to the detection of surface damage usually associated with 'teething' problems during early years of operation; and are often inadequate for detecting in-service degradation or for coating qualification. Furthermore, as CCGT technology is becoming more established, there is a requirement to assess the remnant life of components of which there is currently no suitable technique. This paper describes the inspection technique developed using a multi-frequency eddy current instrument capable of distinguishing between coatings and substrates for the thickness gauging of TBCs to help qualify coatings prior to engine runs. This is a crucial inspection as poor control during coating application can lead to premature failure of the component by thermo-mechanical fatigue, as was the case at a UK CCGT power station. Here, several blades in one particular row which were coated by two different vendors exhibited TMF cracking, however through a thorough investigation with a multi-frequency instrument, it was possible to identify the poorly coated blades and establish that they were all from the single vendor. CR CROWTHER P, 2000, VALIDATION THERMAL B GOLDFINE NJ, 1998, ASM INT GAS TURB TEC HARPER H, 1998, EVALUATION NDT TECHN NR 3 TC 2 PU BRITISH INST NON-DESTRUCTIVE TESTING PI NORTHAMPTON PA 1 SPENCER PARADE, NORTHAMPTON NN1 5AA, NORTHANTS, ENGLAND SN 1354-2575 J9 INSIGHT JI Insight PD SEP PY 2004 VL 46 IS 9 BP 547 EP 549 PG 3 SC Instruments & Instrumentation; Materials Science, Characterization & Testing GA 852XH UT ISI:000223789600015 ER PT J AU Goswami, B Sahay, SK Ray, AK TI Application of thermal barrier coatings on combustion chamber liners - A review. SO HIGH TEMPERATURE MATERIALS AND PROCESSES LA English DT Article DE thermal barrier coating; combustor liner; spallation; emission; thermally grown oxides; remnant life; cooling; ceramics ID GAS-TURBINE BLADES; OXIDATION BEHAVIOR; RESIDUAL-STRESS; BOND COAT; CORROSION BEHAVIOR; CRACK-PROPAGATION; PHASE-COMPOSITION; EB-PVD; MICROSTRUCTURE; NICKEL AB Thermal barrier coatings (TBC) help to reduce the temperature of combustion chamber liner by 473-573K during operation on being aided by swirls of film cooling air. Versatility and low production cost make air plasma spray (APS) TBCs more attractive on liners. However spinal formation at the top to bond coat interface induces ceramic sintering rate and forms thermally grown oxide (TGO) growth. Lifing of engines is attempted to utilize existing design and remnant life within design constrains by giving emphasis on coating philosophies. A proper and efficient substitute with multimetallic bond coat and ceramic topcoat yields longer hours of exposure. Parallel removal of harmful elements in the liner material, restriction on the use of poor quality fuels, and atmospheric effects increase life. Studies of remnant life assessment have been found to be based on control of parameters that check TGO growth, increase adhesion of thicker TGO and restrict ceramic top coat sintering. For example, ceria or lanthana stabilized zirconia transform at comparatively higher temperature than yttria stabilized zirconia. The current scenarios of protection have been changed to replacements by continuous fiber ceramic composite (CFCC), and ceramic matrix composites (CMC) component; e.g. Sylramic, Nicalon, Naxtal, and Ceracurb. Non-destructive examination of ceramic translucence based on Parker's optical property produces in-situ information about ceramic degradations. C1 Natl Met Lab, Jamshedpur 7, Bihar, India. Natl Inst Technol, Dept Met & Mat Sci, Jamshedpur, Bihar, India. RP Goswami, B, Natl Met Lab, Jamshedpur 7, Bihar, India. CR ALI MY, 2001, J MATER SCI, V36, P4535 ATKINSON A, 1991, MATER SCI TECH SER, V7, P1031 BAUFELD B, 2001, SCRIPTA MATER, V45, P859 BENNETT A, 1986, MATER SCI TECH SER, V2, P257 BERNDT CC, 1989, J MATER SCI, V24, P3511 BRANDL W, 1996, SURF COAT TECH 1, V86, P41 BURMAN C, 1988, SURF COAT TECH, V36, P1 CHATTERJEE M, 1993, J MATER SCI, V28, P2803 CHEN MW, 2003, METALL MATER TRANS A, V34, P2289 CHOY KL, 2000, SURFACE ENG, V16, P469 COCKING JL, 1988, SURF COAT TECH, V36, P37 COCKING JL, 1988, SURFACE COATINGS TEC, V36, P133 COHEN H, 1996, GAS TURBINE THEORY, P233 DAVIS G, 2001, ENV PREFERRED ADV GE DIPIETRO S, 1995, CFCC NEWS SUM ELLINGSON WA, 2003, 1 INT C GAS TURB TEC ENDRES W, 1974, P S HIGH TEMP MAT GA, P1 ESBECK DW, 1997, IND ADV TURBINE SYST FEITELBERG AS, DESIGN PERFORMANCE L FUNKENBUSCH AW, 1985, METALL T A, V16, P1964 GILL BJ, 1986, MATER SCI TECH SER, V2, P207 GILL JE, UPRATE OPTIONS MS900 GILL SC, 1990, METALL TRANS B, V21, P377 GODIWALLA KM, 2001, INT J TURBO JET ENG, V18, P77 GROSSKLAUS WD, 1987, HIGH TEMPERATURE COA, P67 HARMSWORTH PD, 1991, J MATER SCI, V26, P3991 HARMSWORTH PD, 1992, J MATER SCI, V27, P611 HARMSWORTH PD, 1992, J MATER SCI, V27, P616 HERMAN H, 1996, METALLURGICAL CERAMI, P261 HICS B, 1987, MAT SCI TECHNOL, V3, P772 HONDERS ED, 1996, PHYS METALLURGY, V2, P1263 ITOH Y, 1999, J SOC MATER SCI JPN, V48, P740 LALIT L, 1989, MAT SCI ENG A-STRUCT, V120, P475 LEE KN, 2002, NASATM2002211372 LEYENS C, 2001, Z METALLKD, V92, P762 LOPEZ E, 1989, J MATER SCI LETT, V8, P346 MALUSH RE, 1988, SURFACE COATINGS TEC, V36, P13 MATEJICEK J, 1999, ACTA MATER, V47, P607 MAVRIS DN, 1997, AM I AER ASTR 35 AER PADTURE NP, 2002, SCIENCE, V296, P280 PALLOS KJ, GER3957B GE PIERCE JL, 2000, J MATER SCI, V35, P2973 PROVENZANO V, 1988, SURF COAT TECH, V36, P61 RABIEI A, 2000, ACTA MATER, V48, P3963 RAO U, 2002, DOD NASA DOE FAA ALL RAY AK, 1998, IN283 INDOGERMAN RAY AK, 1999, J EUR CERAM SOC, V19, P2097 RAY AK, 2000, INT J TURBO JET ENG, V17, P1 RAY AK, 2001, B MATER SCI, V24, P203 SCHULZ U, 2000, MAT SCI ENG A-STRUCT, V276, P1 SIEGEL R, 1997, ID19980219328 NASA SIEGEL R, 1997, THERMAL RAD EFFECTS SIVAKUMAR R, 1989, SURF COAT TECH, V37, P139 SMEGGIL JG, 1988, SURF COAT TECH, V36, P27 SMIALEK JL, 1987, METALL TRANS A, V18, P164 SOHN YH, 2000, METALL MATER TRANS A, V31, P2388 STIGER MJ, 1999, Z METALLKD, V90, P1069 SU YJ, 2001, J MATER SCI, V36, P3511 THOMPSON JA, 1999, UN THERM SPRAY C DUS, P835 THOMPSON JA, 2001, ACTA MATER, V49, P1565 TIEN JK, 1972, METALLURG T, V3, P1587 TOLPYGO VK, 2001, METALL MATER TRANS A, V32, P1467 TOMIMATSU T, 2003, METALL MATER TRANS A, V34, P1739 TRUBELJA ME, DEAC0595OR22426 US D TSUKUDA Y, 2001, TECHNOL REV, V38 WANG D, 1988, SURF COAT TECH, V36, P49 WITHERSPOON L, 2002, SOLAR TURBINES INCOR WU BC, 1989, MAT SCI ENG A-STRUCT, V111, P201 WU BC, 1990, MAT SCI ENG A-STRUCT, V124, P215 WU RC, 1989, MAT SCI ENG A-STRUCT, V111, P201 YASUDA K, 2000, J MATER SCI, V35, P4379 YENNSHONIS TM, 1997, J THERMAL SPRAY TECH, V6, P50 ZHANG Y, 2001, METALL MATER TRANS A, V32, P1724 ZHU D, 1998206633 NASA NR 74 TC 1 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6455 J9 HIGH TEMP MATER PROCESS JI High Temp. Mater. Process. PY 2004 VL 23 IS 3 BP 211 EP 236 PG 26 SC Materials Science, Multidisciplinary GA 852SO UT ISI:000223776900007 ER PT J AU Hou, JS Guo, JT Zhou, LZ Yuan, C Ye, HQ TI Microstructure and mechanical properties of cast Ni-base superalloy K44 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE k44; microstructures; creep; fracture properties ID CREEP; BEHAVIOR AB The Ni-base superalloy K44, developed recently in China, plays an important role in manufacturing blades of gas turbine engines due to its high temperature capability. The microstructure, deformation mechanism and mechanical properties of the Ni-base superalloy K44 have been investigated. Tensile properties and creep behaviors show abnormal variations with increasing temperatures, and the creep data can be fitted well with modified Dyson-McLean relation. transmission electron microscopy (TEM) observations confirmed that these behaviors are affected by the gamma' properties and the deformation mechanism at high temperature. On the basis of creep test results, Larson-Miller and Monkman-Grant plots for life prediction are made. The fracture characteristics of Ni-base superalloy K44 alloy at different temperatures and stress are also studied. (C) 2004 Elsevier B.V. All fights reserved. C1 Chinese Acad Sci, Met Res Inst, Dept Superalloys, Shenyang 110016, Peoples R China. Chinese Acad Sci, Met Res Inst, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China. RP Hou, JS, Chinese Acad Sci, Met Res Inst, Dept Superalloys, Shenyang 110016, Peoples R China. EM jshou@imr.ac.cn CR BALIKCI E, 1999, MAT SCI ENG A-STRUCT, V265, P50 BETTERIDE W, 1974, NIMONIC ALLOYS OTHER, P45 BETTGE D, 1995, Z METALLKD, V86, P190 BROOKS CR, 1982, STRUCTURE PROPERTIES, P139 CASTILLO R, 1987, J ENG GAS TURB POWER, V109, P99 DECKER RF, 1969, STEEL STRENGTHENING, P147 DECKER RF, 1972, SUPERALLOYS, P33 DYSON BF, 1983, ACTA METALL, V31, P18 DYSON BF, 1983, ACTA METALL, V31, P25 JIANTING G, 1983, METALL T A, V14, P2329 KOUL AK, 1984, MATER SCI ENG, V66, P213 LARSON FR, 1952, T ASME, V74, P765 MALDINI M, 1988, SCRIPTA METALL MATER, V22, P1737 MONKMAN FC, 1956, P ASTM, V56, P593 MUKHERJEE AK, 1969, T AM SOC MET, V62, P155 NABARRO FRN, 1995, PHYS CREEP POPE DP, 1984, INT MET REV, V29, P136 SAJJADI SA, 2002, MAT SCI ENG A-STRUCT, V325, P487 SMIALEK JL, 1987, SUPERALLOYS, V2, P291 TIAN SG, 2000, MAT SCI ENG A-STRUCT, V279, P160 NR 20 TC 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 15 PY 2004 VL 374 IS 1-2 BP 327 EP 334 PG 8 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 852EQ UT ISI:000223738400042 ER PT J AU Arakere, NK TI High-temperature fatigue properties of single crystal superalloys in air and hydrogen SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Hot section components in high-performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys such as PWA1480, PWA1484, CMSX-4, and Rene N-4 as these materials provide superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over their polycrystalline counterparts. Fatigue-failures in PWA1480 single crystal nickel-base superalloy turbine blades used in the space shuttle main engine fuel turbopump are discussed. During testing many turbine blades experienced stage II noncrystallographic fatigue cracks with multiple origins at the core leading edge radius and extending down the airfoil span along the core surface. The longer cracks transitioned from stage II fatigue to crystallographic stage I fatigue propagation, on octahedral planes. An investigation of crack depths on the population of blades as a function of secondary crystallographic orientation (beta) revealed that for beta=45 +/- 15 deg tip cracks arrested after some growth or did not initiate at all. Finite element analysis of stress response at the blade tip, as a function of primary and secondary crystal orientation, revealed that there are preferential beta orientations for which crack growth is minimized at the blade tip. To assess blade fatigue life and durability extensive testing of uniaxial single crystal specimens with different orientations has been tested over a wide temperature range in air and hydrogen. A detailed analysis of the experimentally determined low cycle fatigue properties for PWA1480 and SC 7-14-6 single crystal materials as a function of specimen crystallographic orientation is presented at high temperature (75degreesF-1800degreesF) in high-pressure hydrogen and air Fatigue failure parameters are investigated for low cycle fatigue data of single crystal material based on the shear stress amplitudes on the 24 octahedral and 6 cube slip systems for FCC single crystals. The max shear stress amplitude [Deltatau(max)] on the slip planes reduces the scatter in the low cycle fatigue data and is found to be a good fatigue damage parameter, especially at elevated temperatures. The parameter Delta tau(max) did not characterize the room temperature low cycle fatigue data in high-pressure hydrogen well because of the noncrystallographic eutectic failure mechanism activated by hydrogen at room temperature. Fatigue life equations are developed for various temperature ranges and environmental conditions based on power-law curve fits of the failure parameter with low cycle fatigue test data. These curve fits can be used for assessing blade fatigue life. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. RP Arakere, NK, Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. EM nagaraj@ufl.edu CR *PRATT WHIT, 1996, FR245811 P W *PRATT WHIT, 1998, SSME AT HPFTP 1 STAG ARAKERE NK, 2000, ASME J GAS TURBINES COWLES BA, 1996, INT J FRACTURE, P1 CUNNINGHAM S, 1994, CRACK GROWTH LIFE PR, V2 CUNNINGHAM S, 1996, CRACK GROWTH LIFE PR, V1 DALAL RP, 1984, SUPERALLOYS 1984, P185 DELUCA D, 1995, FATIGUE SINGLE CRYST DELUCA DP, 1989, HYDROGEN EFFECTS MAT KEAR BH, 1967, T AIME, V239, P1209 MCLEAN M, 1983, DIRECTIONALLY SOLIDI, P151 MOROSO J, 1999, THESIS U FLORIDA GAI STOUFFER DC, 1996, INELASTIC DEFORMATIO SWANSON G, 2000, TP2000210074 TP TELESMAN J, 1995, INT GAS TURBINE AERO VERSNYDER FL, 1960, T ASM, V52, P485 NR 16 TC 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 2004 VL 126 IS 3 BP 590 EP 603 PG 14 SC Engineering, Mechanical GA 848KL UT ISI:000223466200017 ER PT J AU Claudio, RA Branco, CM Gomes, EC Byrne, J Harrison, GF Winstone, MR TI Fatigue life prediction and failure analysis of a gas turbine disc using the finite-element method SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE dysfunction criteria; finite-element analysis; fracture mechanics; gas-turbine disc; J-integral; life prediction ID CRACK-GROWTH AB A numerical prediction of the life of a gas turbine model disc by means of the finite-element technique is presented and the solution is compared with an experimental rim-spinning test. The finite-element method was used to obtain the K solution for a disc with two types of cracks, both at the notch root of the blade insert and located in the corner and in the centre. A crack aspect ratio of (a/c) = 1 was assumed. The fracture mechanics parameters F-integral and K were used in the assessment, which were computed with linear elastic and elastic-plastic material behaviour. Using a crack propagation program with appropriate fatigue-creep crack growth-rate data, previously obtained in specimens for the nickel-based superalloy IN718 at 600 degreesC, fatigue life predictions were made. The predicted life results were checked against experimental data obtained in real model discs. The numerical method, based on experimental fatigue data obtained in small laboratory specimens, shows great potential for development, and maybe able to reduce the enormous costs involved in the testing of model and full-size components. C1 Inst Politecn Setubal, EST, Dept Mech Engn, P-2910761 Setubal, Portugal. Inst Super Tecn, Dept Mech Engn, P-1096 Lisbon, Portugal. Univ Portsmouth, Dept Mech & Design Engn, Portsmouth PO1 3DJ, Hants, England. QinetiQ, Farnborough, Hants, England. DSTL, Farnborough, Hants, England. RP Claudio, RA, Inst Politecn Setubal, EST, Dept Mech Engn, Campus IPS, P-2910761 Setubal, Portugal. EM rclaudio@est.ips.pt CR ANTUNES FV, 1999, THESIS TU COIMBRA PO ANTUNES FV, 2000, MAT HIGH TEMP, V4, P439 ANTUNES FV, 2001, FATIGUE FRACT ENG M, V24, P127 BLUML P, 1999, QUALIFICATION LIFE E BOYDLEE AD, 1999, QUALIFICATION LIFE E BRANCO CM, 1996, HIGH TECHNOLOGY SERI, V315, P93 BRANCO CM, 1999, MAT HIGH TEMP, V16, P1 CLAUDIO RA, 2001, THESIS TU LISBON POR CLAUDIO RA, 2002, 8 PORT C FRACT UTAD DAVENPORT O, 2000, RECOMMENDED PRACTICE EVANS WJ, 2000, J ENG INTEGRITY SOC, V8, P16 HARRISON G, 2000, RECOMMENDED PRACTICE HARRISON GF, 1999, P C LIF ASS HOT SECT, P11 HARRISON GF, 1999, P DERA S GAS TURB MA HARRISON GF, 2000, FATIGUE 2002 FRACTUR, P15 HODGKINSON V, 1997, THESIS U PORTSMOUTH LIBURDI J, 1999, QUALIFICATION LIFE E NICHOLAS T, 1999, QUALIFICATION LIFE E PATNAIK PC, 1999, QUALIFICATION LIFE E POMMIER S, 1999, INT J FATIGUE, V21, P243 TSCHIRNE KU, 1999, QUALIFICATION LIFE E ZHUANG WZ, 2000, INT J FATIGUE, V22, P241 NR 22 TC 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD SEP PY 2004 VL 27 IS 9 BP 849 EP 860 PG 12 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 848MW UT ISI:000223472800011 ER PT J AU Forest, AE White, AJ Lai, CC Guo, SM Oldfield, MLG Lock, GD TI Experimentally aided development of a turbine heat transfer prediction method SO INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW LA English DT Article DE heat transfer; turbine; computational prediction AB In the design of cooled turbomachinery blading a central role is played by the computer methods used to optimise the aerodynamic and thermal performance of the turbine aerofoils. Estimates of the heat load on the turbine blading should be as accurate as possible, in order that adequate life may be obtained with the minimum cooling air requirement. Computer methods are required which are able to model transonic flows, which are a mixture of high temperature combustion gases and relatively cool air injected through holes in the aerofoil surface. These holes may be of complex geometry, devised after empirical studies of the optimum shape and the most cost effective manufacturing technology. The method used here is a further development of the heat transfer design code (HTDC), originally written by Rolls-Royce plc under subcontract to Rolls-Royce Inc for the United States Air Force. The physical principles of the modelling employed in the code are explained without extensive mathematical details. The paper describes the calibration of the code in conjunction with a series of experimental measurements on a scale model of a high-pressure nozzle guide vane at non-dimensionally correct engine conditions. The results are encouraging, although indicating that some further work is required in modelling highly accelerated pressure surface flow. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Bath, Fac Engn & Design, Dept Mech Engn, Bath BA2 7AY, Avon, England. Rolls Royce PLC, Derby DE2 8BJ, England. Univ Oxford, Dept Engn Sci, Oxford OX1 2JD, England. RP Lock, GD, Univ Bath, Fac Engn & Design, Dept Mech Engn, Bath BA2 7AY, Avon, England. EM g.d.lock@bath.ac.uk CR AMES FE, 1990, 138 ASME HTD CEBECI T, 1974, APPL MATH MECH, V15 CHAPMAN C, 1952, MATH THEORY NONUNIFO CRAWFORD ME, 1980, 80GT44 ASME 2 ECKERT D, 1959, HEAT MASS TRANSFER, P457 FOREST AE, 1977, CP224 AGARD GUO SM, 1998, INT J HEAT FLUID FL, V19, P594 GUO SM, 2000, J TURBOMACH, V122, P709 KULISA P, 1991, 91GT143 ASME LAPWORTH BL, 1997, 13 INT S AIR BREAT 2 LAPWORTH BL, 1999, 14 INT AIR BREATH 2 MARTINEZBOTAS RF, 1993, 93GT248 ASME OLDFIELD MLG, 1997, 214197 OUEL PATANKAR SV, 1970, HEAT MASS TRANSFER B REYHNER TA, 1968, INT J NONLINEAR MECH, V3, P173 ROWBURY DA, 2001, ASME, V123, P258 NR 16 TC 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0142-727X J9 INT J HEAT FLUID FLOW JI Int. J. Heat Fluid Flow PD AUG PY 2004 VL 25 IS 4 BP 606 EP 617 PG 12 SC Thermodynamics; Engineering, Mechanical; Mechanics GA 847MS UT ISI:000223397600004 ER PT J AU Hashizume, R Yoshinari, A Murata, Y Morinaga, M TI Development of Ni-based single crystal superalloys for power-generation gas-turbine blades SO TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN LA Japanese DT Article DE gas turbine blade; Ni-based superalloy; d-electrons concept; single-crystal; creep strength; oxidation resistance; burner rig test; hot corrosion resistance AB In advanced industrial gas-turbine systems, there has been a great demand for new single crystal (SC) superalloys with an excellent combination of high-temperature creep strength, hot-corrosion resistance and oxidation resistance. In this study, ten nickel-based SC superalloys were designed with the aid of the d-electrons concept. Their chemical compositions were in the range of 1.2-1.5% Ti, 3.8-6.5% Cr, 11% Co, 01.4% Mo, 6.5-7.4% Ta, 5.0-6.0% W, 3.6-5.4% Re, 5.1-5.5% Al, 0.12-0.14% Hf and balanced Ni in mass% units. A series of experiments such as creep rupture tests, burner rig tests and cyclic oxidation tests was conducted with the heat-treated SC specimens of these alloys. All the designed alloys were found to be superior in the creep rupture life to a second generation superalloy, CMSX-4. In the hot-corrosion resistance estimated from the burner rig tests, any designed alloys were comparable or even superior to CMSX-4. The oxidation resistance was very different amount the designed alloys, but some of them showed higher resistance than CMSX-4. Thus the SC alloys containing about 4-5 mass% Re had about 20 K higher temperature capability than CMSX-4, while exhibiting excellent hot-corrosion resistance and oxidation resistance. C1 Kansai Elect Power Co Inc, Power Engn R&D Ctr, Amagasaki, Hyogo 6610974, Japan. Nagoya Univ, Grad Sch Engn, Nagoya, Aichi, Japan. RP Hashizume, R, Kansai Elect Power Co Inc, Power Engn R&D Ctr, 3-11-20 Nakoji, Amagasaki, Hyogo 6610974, Japan. CR AOKI Y, 2003, P 8 INT GAS TURB C 2, TS118 ERICKSON GL, 1996, SUPERALLOYS 1996, P45 HARADA H, COMMUNICATION HINO T, 2002, MAT ADV POWER ENG 20, P303 HINO T, 2003, P 8 INT GAS TURB C 2, TS123 KOIZUMI Y, 2003, P 8 INT GAS TURB C 2, TS119 LILLERUD KP, 1982, OXID MET, V17, P127 MATSUGI K, 1992, SUPERALLOYS 1992, P307 MONIRUZZAMAN M, 2002, ISIJ INT, V42, P1018 MONIRUZZAMAN M, 2002, ISIJ INT, V43, P386 MORINAGA M, 1984, J PHYS SOC JPN, V53, P653 MURATA Y, 2000, SUPERALLOYS 2000, P285 WALSTON WS, 1996, SUPERALLOYS 1996, P9 YOSHINARI A, 2003, P 8 INT GAS TURB C 2, TS126 NR 14 TC 1 PU IRON STEEL INST JAPAN KEIDANREN KAIKAN PI TOKYO PA 9-4 OTEMACHI 1-CHOME CHIYODA-KU, TOKYO, 100, JAPAN SN 0021-1575 J9 TETSU TO HAGANE JI Tetsu To Hagane-J. Iron Steel Inst. Jpn. PD JUL PY 2004 VL 90 IS 7 BP 518 EP 525 PG 8 SC Metallurgy & Metallurgical Engineering GA 836OM UT ISI:000222565300009 ER PT J AU Bacos, MP Josso, P Vialas, N Poquillon, D Pieraggi, B Monceau, D Nicholls, JR Simms, N Encinas-Oropesa, A Ericsson, T Stekovic, S TI ALLBATROS advanced long life blade turbine coating systems SO APPLIED THERMAL ENGINEERING LA English DT Article DE MCrAlY; aluminium; oxidation; corrosion; thermo-mechanics; turbine ID BURNER RIG; PLANT ENVIRONMENTS; EROSION DAMAGE; METHODOLOGY; CORROSION AB The scientific and technological objectives of this program are to increase the efficiency, reliability and maintainability of industrial gas turbine blades and vanes by developing coatings that can warrant a 50 000 h life, i.e. twice that of the usual life, of the hot components (800-1100 degreesC) even with the use of renewable fuels such as biomass gas or recovery incinerator gas i.e. low-grade fuels with high pollutant levels, characterising advanced existing coatings to assess lifetime and performance of coatings and coated materials, providing material coating data and design criteria to use coating as a design element, increasing the fundamental understanding of the behaviour of coated materials, their degradation, fracture mechanisms and engineering because of the strong need for a mechanism-based modelling of durability. These programmes permitted the selection of two reference coatings and the development of two innovative coatings. Concurrently work has been done in order to develop corrosion, oxidation and thermo-mechanical property models. Correlations between coatings development, experimental results and calculations will be discussed. (C) European Communities, 2004. Published by Elsevier Ltd. All rights reserved. C1 Off Natl Etud & Rech Aerosp, F-92322 Chatillon, France. Inst Natl Polytech Toulouse, ENSIACET, CIRIMAT, F-31077 Toulouse, France. Cranfield Univ, Cranfield MK43 0AL, Beds, England. Linkoping Univ, S-58183 Linkoping, Sweden. RP Bacos, MP, Off Natl Etud & Rech Aerosp, 29 Avde Div Leclerc,BP 72, F-92322 Chatillon, France. EM bacos@onera.fr CR BACOS MP, 2003, SURF COAT TECH, V162, P248 GIRARD B, 2807073, FR MONCEAU D, 1998, OXID MET, V50, P477 POQUILLON D, 2003, OXID MET, V59, P409 SIMMONSMACKIE N, 2001, LANGUAGE INTERVENTIO, P246 SIMMS NJ, 2000, ELEC SOC S, V99, P305 SIMMS NJ, 2000, MATER HIGH TEMP, V17, P355 SIMMS NJ, 2001, MATER SCI FORUM 1&2, V369, P833 VAALER LE, 1946, T ELECTROCHEM SOC, V90, P43 NR 9 TC 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD AUG PY 2004 VL 24 IS 11-12 BP 1745 EP 1753 PG 9 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA 838MR UT ISI:000222717900018 ER PT S AU Kim, CS Kim, JK TI Reliability analysis of steam turbine blade using Monte Carlo simulation SO ADVANCES IN FRACTURE AND FAILURE PREVENTION, PTS 1 AND 2 SE KEY ENGINEERING MATERIALS LA English DT Article DE degradation; finite element analysis; Weibull distribution; Monte Carlo simulation; strength-stress interference model ID FATIGUE LIFE; STEEL AB In this study, the reliability analysis of the low pressure steam turbine blade was performed using the Monte Carlo simulation considering variations of applied stress and strength. Applied stress under the service condition of steady state was obtained by finite element analysis. The fatigue strength under rotating bending load was evaluated by the staircase method. The most appropriate probabilistic distribution of the fatigue strength is 3-parameter Weibull distribution, which is determined by the comparative analysis. The failure probability under various loading conditions was derived from the strength-stress interference model. C1 Korea Natl Railrd Coll, Dept Rolling Stocks Mech Engn, Uiwang Si 437763, Kyungki Do, South Korea. Hanyang Univ, Sch Mech Engn, Seoul 133791, South Korea. RP Kim, CS, Korea Natl Railrd Coll, Dept Rolling Stocks Mech Engn, Uiwang Si 437763, Kyungki Do, South Korea. EM chalskim@krc.ac.kr kimj@hanyang.ac.kr CR *KEPCO POW RES I, 1997, TECHN REP REL TURB B, P11 CONGLETON J, 1990, INT J FATIGUE, V12, P91 DOWLING NE, 1993, MECH BEHAV MAT, P444 GRANT J, 1988, TITANIUM STEAM TURBI, P149 HALDAR A, 2000, PROBABILITY RELIABIL, P250 JOHN R, 1996, METALS HDB, V8, P701 KERREBROCK JL, 1989, AIRCRAFT ENGINES GAS, P189 KIM HJ, 1998, P KSME MAT FRACT 1, P5 NORTON RL, 2000, MACH DES, P345 SHU HD, 1992, RELIABILITY ANAL ENG, P22 THAUVIN G, 1996, P 6 INT FAT C, V2, P1171 VYAS NS, 1994, J ENG GAS TURB POWER, V116, P198 ZHAO YX, 1998, FATIGUE FRACT ENG M, V21, P781 ZHAO YX, 2000, RELIAB ENG SYST SAFE, V12, P1 NR 14 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2004 VL 261-263 PN Part 1&2 BP 549 EP 554 PG 6 SC Materials Science, Ceramics; Materials Science, Composites GA BAC70 UT ISI:000221573900089 ER PT S AU Li, T Yue, ZF TI A life prediction model for nickel-base single crystal superalloy DD3 SO ADVANCES IN FRACTURE AND FAILURE PREVENTION, PTS 1 AND 2 SE KEY ENGINEERING MATERIALS LA English DT Article DE nickel-base single crystal superalloy; life prediction model; thermal fatigue creep ID FATIGUE AB The possibility of the life prediction model for nickel-base single crystal blades has been studied. The fatigue-creep (FC) and thermal fatigue-creep (TMFC) as well as creep experiments have been carried out with different hold time of DD3. The hold time and the frequency as well as the temperature range are the main factors influencing on the life. An emphasis has been put on the micro mechanism of the rupture of creep, FC and TMFC. Two main factors are the voiding and degeneration of the material for the creep, FC and TMFC experiments. There are voids in the fracture surfaces, and size of the voids is dependent on the loading condition. Generally, the rupture mechanism is the same for creep, FC and TMFC. If the loading can be simplified to the working conditions of the turbine blades, i.e. the hold time is at the top temperature and maximum stress, a linear life model is satisfactory to the life prediction of nickel-base single crystal superalloy from the experimental study in this paper. The temperature and the stress level of the nickel-base single crystal (SC) blades are not uniform. To predict the life of SC blades, one should consider the cycles of the temperature and stress as well as the oxidation simultaneously. In the past 30 years, there are many works on the mechanical behavior and description, such as the inelastic constitutive relationships, plastic, fracture, isothermal creep and fatigue and thermal fatigue as well as oxidation([1-3]). There are also special software (program) to analyze the deformation and life of nickel-base single crystal structures, such as blades. In order to apply to the engineering more conveniently, there should be a life prediction model for the blades. The model should not be too complex, but take more influential factors as possible into consideration. C1 SW Univ Sci & Tech, Coll Civil Engn, Mianyang 621000, Peoples R China. Northwestern Polytech Univ, Dept Engn Mech, Xian 710072, Peoples R China. RP Li, T, SW Univ Sci & Tech, Coll Civil Engn, Mianyang 621000, Peoples R China. CR KRAFT S, 1993, FATIGUE FRACT ENG M, V16, P237 MARCHAND N, 1988, ASTM STP, V942, P638 SEHITOGLU H, 1992, ASTM STP, V1122, P47 YEU ZF, 2000, STUDIES MECH BEHAV N YUE ZF, 1995, METALL MATER TRANS A, V26, P1815 YUE ZF, 1998, METALL MATER TRANS A, V29, P1093 YUE ZF, 2001, COLLECTION EXPT DATA NR 7 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2004 VL 261-263 PN Part 1&2 BP 1123 EP 1128 PG 6 SC Materials Science, Ceramics; Materials Science, Composites GA BAC70 UT ISI:000221573900178 ER PT J AU Philippidis, TP Vassilopoulos, AP TI Life prediction methodology for GFRP laminates under spectrum loading SO COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING LA English DT Article DE glass fibers; fatigue; damage accumulation; variable amplitude loading ID FATIGUE LIFE; STRESS; DAMAGE AB A complete life prediction methodology for glass fiber reinforced plastic laminates accounting for plane stress states and spectrum loading is presented in this paper. Fatigue strength allowables in the laminate symmetry axes are derived by direct characterization for a number of different constant amplitude loading cases. Experimental results from tests inducing plane stress states, conducted using two different loading spectra of variable amplitude, were used to validate the entire methodology. The first loading spectrum is a modified version of the well known in wind turbine rotor blade research activities, WISPERX, while the second one is derived through aeroelastic simulations of a realistic loading case for a small glass fiber reinforced polyester rotor blade. The effectiveness of the methodology is investigated and correlated to several parameters that affect life prediction, such as, type of loading, baseline data, damage accumulation rule, etc. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Patras, Dept Mech & Aeronaut Engn, Sect Appl Mech, Rion 26504, Greece. RP Philippidis, TP, Univ Patras, Dept Mech & Aeronaut Engn, Sect Appl Mech, POB 1401,Univ Campus, Rion 26504, Greece. EM philippidis@mech.upatras.gr CR ADAM T, 1994, INT J FATIGUE, V16, P533 BOND IP, 1999, COMPOS PART A-APPL S, V30, P961 BOND IP, 2000, INT J FATIGUE, V22, P633 HWANG W, 1986, J COMPOS MATER, V20, P125 KENSCHE CW, 1994, EUR WIND EN C P, V1, P738 MADSEN PH, 1990, RECOMMENDED PRACTICE NIJSSEN RPL, 2002, ASME WIND EN S REN N OCH F, 1993, AGARDOGRAPH, V292 OWEN MJ, 1972, J PHYS D, V5, P1637 PHILIPPIDIS TP, 573 EPET PHILIPPIDIS TP, 1999, J COMPOS MATER, V33, P1578 PHILIPPIDIS TP, 2002, INT J FATIGUE, V24, P813 PHILIPPIDIS TP, 2002, INT J FATIGUE, V24, P825 RIZIOTIS VA, 2000, J WIND ENG IND AEROD, V85, P211 SCHAFF JR, 1997, J COMPOS MATER, V31, P158 SENDECKYJ GP, 1991, COMPOSITE MAT SERIES, V4 SIMS DF, 1977, ASTM STP, V636, P185 TENHAVE AA, 1988, 10 BWEA C LOND UK 23 TENHAVE AA, 1988, EUR COMM WIND EN C P, P448 NR 19 TC 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-835X J9 COMPOS PART A-APPL SCI MANUF JI Compos. Pt. A-Appl. Sci. Manuf. PY 2004 VL 35 IS 6 BP 657 EP 666 PG 10 SC Engineering, Manufacturing; Materials Science, Composites GA 818NN UT ISI:000221251900005 ER PT S AU Wallace, JM Mavris, DN Schrage, DP TI System reliability assessment using covariate theory SO ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM, 2004 PROCEEDINGS SE PROCEEDINGS : ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article DE system reliability; accelerated life testing; covariate models; joint probability AB A method is demonstrated that utilizes covariate theory to generate a multi-response component failure distribution as a function of pertinent operational parameters. Where traditional covariate theory uses actual measured life data, a modified approach is used herein to utilize life values generated by computer simulation models. The result is a simulation-based component life distribution function in terms of time and covariate parameters for each failure response. A multivariate joint probability covariate model is proposed by combining the covariate marginal failure distributions with the Nataf transformation approach. Evaluation of the joint probability model produced significant improvement in joint probability predictions as compared to the independent series event approach. The proposed methods are executed for a nominal aircraft engine system to demonstrate the assessment of multi-response system reliability driven by a dual mode turbine blade component failure scenario as a function of operational parameters. C1 Georgia Tech, Sch Aerosp Engn, Atlanta, GA 30332 USA. RP Wallace, JM, Georgia Tech, Sch Aerosp Engn, 270 Ferst Dr, Atlanta, GA 30332 USA. EM jonw@asdl.gatech.edu dimitri.mavris@ae.gatech.edu daniel.schrage@ae.gatech.edu CR GOLLWITZER S, 1988, PROBALISTIC ENG MECH, V3, P98 LEEMIS LM, 1995, RELIABILITY PROBABIL LIU PL, 1986, PROBALISTIC ENG MECH, V1, P105 MEEKER WQ, 1998, STAT METHODS RELIABI MORROW J, 1968, FATIGUE DESIGN HDB A, V4, P21 NATAF A, 1962, CR HEBD ACAD SCI, V225, P42 PAINTON L, 1995, IEEE T RELIAB, V44, P172 SETHURAMAN J, 1982, J AM STAT ASSOC, V77, P204 STEPHENS MA, 1974, J AM STAT ASSOC, V69, P730 NR 9 TC 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-144X J9 P A REL MAI PY 2004 BP 18 EP 24 PG 7 SC Engineering, Multidisciplinary GA BY64B UT ISI:000189427800004 ER PT J AU Lattime, SB Steinetz, BM TI High-pressure-turbine clearance control systems: Current practices and future directions SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Improved blade-tip sealing in a high-pressure compressor and high-pressure turbine can provide dramatic improvements in specific fuel consumption, time on wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1 million. Removal of engines from service is primarily due to the spent exhaust gas temperature margin caused mainly by the deterioration of high-pressure-turbine components. Increased blade-tip clearance is a major factor in hot-section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero-gas-turbine engine high-pressure-turbine performance degradation and the mechanisms that promote these losses are presented. Benefits to the high-pressure turbine due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next-generation engine clearance control systems. C1 Ohio Aerosp Inst, NASA Glenn Res Ctr, Cleveland, OH 44142 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Lattime, SB, Ohio Aerosp Inst, NASA Glenn Res Ctr, MS 23-3,21000 Brookpk Rd, Cleveland, OH 44142 USA. CR *FED AV ADM DEP TR, 1971, 5493 FR *NUR TRANSP STAT, AIR CARR FIN REP FOR *ROCK MOUNT I, 2002, CLIM AIR TRAV EM CARPENTER KD, 1997, 5639210, US CATLOW R, 5211534, US CAWLEY JD, 1985, 4540336, US CIOKAJLO JJ, 1992, 5116199, US EDER M, 1997, AVIATION FUELS IMPRO, P61 FASCHING WA, 1982, CR165612 NASA FLOTOW A, 2000, AEROSP C P, V6, P433 GAFFIN WO, 1979, CR159661 NASA HALILA EE, 1982, CR167955 NASA HOWARD WD, 1982, CR165581 NASA HUBER FW, 1997, 5667359, US JORGENSEN PJ, 1962, J CHEM PHYS, V37 KAWECKI EJ, 1979, AFAPLTR792087 KOLTHOFF P, 1962, 3039737, US MARTIN RL, 1981, CR165760 NASA MCNAMARA S, 2000, ERA FAST FACTS WEB P OLSSON WJ, 1982, CR165573 NASA TSENG W, 1991, 5035573, US WARDLE RL, 1960, 2927724, US WISEMAN MW, 2001, P AM CONTR C, V5, P3706 NR 23 TC 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAR-APR PY 2004 VL 20 IS 2 BP 302 EP 311 PG 10 SC Engineering, Aerospace GA 805MB UT ISI:000220369300013 ER PT J AU DiCristoforo, PE Elledge, M TI Stress redistribution for increased creep life in the GE MS6001 B second-stage blade SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB When a hot end blade for a gas turbine is designed, several failure criteria must be considered to insure reliability. The criteria include (but are not limited to) creep rupture, low-cycle fatigue, high-cycle fatigue, and creep deflection. This paper will focus on the second-stage turbine blade for the GE MS6001 industrial gas turbine. BP Amoco has experienced failure of this blade due to excessive creep deflection. Creep deflection rate is a function of stress level and metal temperature. A typical approach to reducing creep deflection is to reduce the bulk temperature in the blade. In this paper a design is reviewed that has had the stress redistributed, so that the high-temperature regions of the airfoil are at a lower stress level, thereby reducing the creep rate to an acceptable level. C1 TurboCare, Chicopee, MA USA. BP Amoco Chem, Dickinson, TX 77539 USA. RP DiCristoforo, PE, TurboCare, 2140 Westover Rd, Chicopee, MA USA. CR GRANACHER J, 1987, ADV MAT TECHNOLOGY F, P511 JAQUEWAY JK, 1997, IGTI TURB EXP ORL FL WEBB RL, 1971, INT J HEAT MASS TRAN, V14, P601 WHITE FM, 1984, HEAT TRANSFER NR 4 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2004 VL 126 IS 1 BP 127 EP 130 PG 4 SC Engineering, Mechanical GA 803NF UT ISI:000220237100019 ER PT J AU Gao, Y Xie, L Zeng, F TI Formation and behavior of thermal barrier coatings on nickel-base superalloys SO TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA LA English DT Article DE magnetron sputtering; thermal barrier coating; shot peening; high temperature oxidation AB Plasma-sprayed thermal barrier coatings (TBCs) have been used to extend the life of combustors. Electron beam physical vapor deposited (EB-PVD) ceramic coating has been developed for more demanding rotating as well as stationary turbine components. Here 3 kW RF magnetron sputtering equipment was used to gain zirconia ceramic coatings on hollow turbine blades and vanes, which had been deposited NiCrAlY by cathodic are deposition. NiCrAlY coating surface was treated by shot peening; the effects of shot peening on the residual stress are presented. The results show that RF sputtered TBCs are columnar ceramics, strongly bonded to metal substrates. NiCrAlY bond coat is made of beta, gamma' and Cr phases, ZrO2 ceramic layer consists of t' and c phases. No degradation occurs to RF ceramic coatings after 100 h high temperature oxidation at 1150 degreesC and 500 thermal cycles at 1150 degreesC for 2 min, air-cooling. C1 Tsing Hua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. Univ Sci & Technol Beijing, Sch Informat, Beijing 100083, Peoples R China. RP Gao, Y, Tsing Hua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. EM ygao@tsinghua.edu.cn CR CELIK E, 1997, SURF COAT TECH, V97, P361 DIAZ P, 1998, MATER CHARACT, V41, P55 GAO Y, 1999, MATER MANUF PROCESS, V14, P691 HERR W, 1997, SURF COAT TECH, V97, P335 KARLSSON AM, 2002, ACTA MATER, V50, P1211 KHOR KA, 2000, THIN SOLID FILMS, V372, P104 KOKINI K, 2002, SURF COAT TECH, V154, P223 LUGSCHEIDER E, 1998, SURF COAT TECH, V98, P1221 MA CH, 2002, THIN SOLID FILMS, V418, P73 MOVCHAN BA, 1998, SURF COAT TECH, V100, P309 SCHULZ U, 1996, SURF COAT TECH, V82, P259 ZHOU YC, 2002, INT J FATIGUE, V24, P407 ZHU DM, 2001, SURF COAT TECH, V138, P1 NR 13 TC 1 PU ALLERTON PRESS INC PI NEW YORK PA 18 WEST 27TH ST, NEW YORK, NY 10001 USA SN 1003-6326 J9 TRANS NONFERROUS METAL SOC CH JI Trans. Nonferrous Met. Soc. China PD FEB PY 2004 VL 14 IS 1 BP 44 EP 48 PG 5 SC Metallurgy & Metallurgical Engineering GA 800NI UT ISI:000220034600009 ER PT J AU Lin, CH TI Prediction of corrosion fatigue damages for turbine blades subjecting to randomly distributed power system unbalance SO JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING LA English DT Article DE turbine blade; power system unbalance; corrosion fatigue; reliability ID TORSIONAL FATIGUE; GENERATOR SHAFTS AB In this paper, a fatigue damage estimation procedure is implemented by integrating the results of an EPRI and a GE testing reports as well as a shareware developed by the Oslo University, which is incorporated with a verified transient simulation program developed by the Aberdeen University to study the effects of power system unbalance on turbine blade damaging. Based on the Weibull distribution in the negative sequence current (I-2) and the operational environment containing 22% NaCl, the probability level of fatigue life as well as the reliability against fatigue failure for the long blades of low-pressure (LP) turbine are evaluated. It is shown that even though the blades could withstand the most serious impact arising from three-phase-to-ground fault, still it cannot guarantee adequate long-term reliability in the normal operational condition. C1 Kao Yuan Inst Technol, Dept Elect Engn, Kaohsiung 82101, Taiwan. RP Lin, CH, Kao Yuan Inst Technol, Dept Elect Engn, 1821 Chungshan Rd, Kaohsiung 82101, Taiwan. EM lin_chi_hshiung@hotmail.com CR 1982, STEAM TURBINE DISC C, V1 *MPR ASS INC, 1996, MPR1719 BATES RC, 1984, CS2932 EPRI CHYN C, 1996, IEE P-GENER TRANSM D, V143, P479 CONN AF, 1973, ASTM STP, V520, P273 CRAMER E, 942032 DET NORSK VER DEWEY RP, 1985, CS3891 EPRI GRAN S, 1992, COURSE OCEAN ENG JACKSON MC, 1979, IEEE T PAS, V98, P2299 JONAS O, 1981, WORKSH CORR FAT STEA LIN CH, 2000, INT J ELEC POWER, V22, P435 PLACEK RJ, 1984, EL3083 EPRI SMITH JR, 1986, IEEE T ENERGY CONVER, V1, P152 SMITH SH, 1983, ASTM STP, V791, P120 TSAO TP, 1988, PREDICTION TERMINAL WILLIAMS RA, 1986, IEEE T ENERGY CONVER, V1, P80 YU MS, 1992, METALLURGICAL ANAL F NR 17 TC 0 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1344-7912 J9 JSME INT J A-SOLID MECH MAT E JI JSME Int. J. Ser. A-Solid Mech. Mat. Eng. PD JAN PY 2004 VL 47 IS 1 BP 70 EP 78 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 779JA UT ISI:000189290500010 ER PT J AU Tsai, JI Lin, CH Tsao, TP TI Assessment of long-term life expenditure for steam turbine shafts due to noncharacteristic subharmonic currents in asynchronous links SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article DE electromagnetic torque (E/M torque); fatigue life expenditure; harmonics; HVDC; torsional vibration; turbine shaft ID GENERATOR-EXCITER SHAFTS; DC CURRENTS; HVDC LINKS; TORSIONAL OSCILLATIONS; FATIGUE; DISTURBANCES; EXCITATION; TORQUES; BLADES AB In this paper, the long-term effect of noncharacteristic subharmonic currents in a HVDC link on the fatigue life loss in turbine-generator shafts is analyzed. As soon as the asynchronous operation in HVDC links takes place, the disturbing rotor frequency distributions on both ac sides of the main harmonics are, exactly subsynchronous. To completely investigate the long-term effects of inevitable asynchronous operation, a systematic scheme is motivated to examine the concerned fatigue life expenditure level. The simulation results show the influences under various operating conditions and prove the potential long-term failure of shafts due to such electrical disturbances. It is also justified that even though the shafts could withstand the most severe impact subject to a three-phase-to-ground fault, it still cannot guarantee long-term safety operations even under normal operating conditions. C1 Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. Kao Yuan Inst Technol, Dept Elect Engn, Kaohsiung 82101, Taiwan. RP Tsai, JI, Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. EM t1026719@ms83.url.com.tw CR 2001, POWER SYSTEM BLOCKSE *CIGRE IEEE JOINT, 1992, CIGRE PUBL, V68 *IEEE SYBS RES WOR, 1985, IEEE T POW APP SYST, V104, P1327 *MPR ASS INC, 1996, MPR1719 MPR ASS INC ANDERSON PM, 1990, SUBSYNCHRONOUS RESON ARRILLAGA J, 1983, HIGH VOLTAGE DIRECT CANKEY IM, 1980, IEEE T POWER APP SYS, V99, P1357 CHYN C, 1996, IEE P-GENER TRANSM D, V143, P479 FARIED SO, 1996, IEE P-GENER TRANSM D, V143, P487 GONZALEZ AJ, 1984, IEEE T POWER AP SYST, V103, P3218 HAMMONS TJ, 1983, IEEE T POWER AP SYST, V102, P1552 HAMMONS TJ, 1994, IEEE T ENERGY CONVER, V9, P503 HAMMONS TJ, 1995, IEEE T ENERGY CONVER, V10, P95 HAMMONS TJ, 1995, IEEE T POWER SYST, V10, P1572 HAMMONS TJ, 1997, ELECTR MACH POW SYST, V25, P87 JOYCE JS, 1980, IEEE T PAS, V99, P111 LAMBRECHT D, 1982, IEEE T POWER AP SYST, V101, P3689 MASRUR MA, 1991, P I ELECT ENG C, V138, P4756 PLACEK RJ, 1984, EL3083 EPRI SMITH JR, 1986, IEEE T ENERGY CONVER, V1, P152 TSAO TP, 2000, IEE P-SCI MEAS TECH, V147, P229 WILLIAMS RA, 1986, IEEE T ENERGY CONVER, V1, P80 YACAMINI R, 1986, IEE PROC-C, V133, P301 NR 23 TC 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8950 J9 IEEE TRANS POWER SYST JI IEEE Trans. Power Syst. PD FEB PY 2004 VL 19 IS 1 BP 507 EP 516 PG 10 SC Engineering, Electrical & Electronic GA 773XN UT ISI:000188951000064 ER PT J AU Harrison, GF Tranter, PH Shepjerd, DP Ward, T TI Application of multi-scale modelling in aeroengine component life assessment SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE multi-scale modelling; single crystal; component lifing; creep; fatigue; composites ID COMPOSITE AB The paper provides an overview of the procedures used to determine the safe service lives of aeroengine components, with particular reference to the role of scale in lifing models. It is shown how the volume of material tested influences the declared service life of fracture critical components. The development of a combined micromechanical-macromechanical model for the life assessment of the anisotropic behaviour of advanced single crystal turbine blade materials is discussed. The role of micro-scale modelling in predicting the low cycle fatigue (LCF) behaviour of long fibre metal matrix composite components is also discussed. The final case considered is that of al microstructural model used in the life assessment of ceramic matrix composites. (C) 2003 Elsevier B.V. All rights reserved. C1 Airworthiness & Structural Integrity QinetiQ, Farnborough GU14 0LX, Hants, England. RP Harrison, GF, Airworthiness & Structural Integrity QinetiQ, Farnborough GU14 0LX, Hants, England. EM gfharrison@qinetiq.com CR *CIV AV AUTH, 1986, JOINT EUR AIRW REQ E DANIELS HE, 1945, P ROY SOC LOND A MAT, V183, P404 EVANS AG, 1989, ACTA METALL MATER, V37, P2567 EVANS WJ, 1984, P 2 INT C CREEP FRAC GALAMBOS J, 1987, ASYMPTOTIC THEORY EX HARRISON GF, 1986, P INT C DES TIT I ME HENSTENBURG RB, 1989, POLYM COMPOSITE, V10, P389 HOMEWOOD T, 1999, MODELLING MICROSTRUC PHOENIX SL, 1992, ACTA METALL MATER, V40, P2813 SCHWEIGER G, 1986, INT J FATIGUE, V4 SEPHERD DP, 2001, P RTO M MON MAN GAS NR 11 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2004 VL 365 IS 1-2 BP 247 EP 256 PG 10 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 762KZ UT ISI:000187972000036 ER PT J AU Issler, S Roos, E TI Numerical and experimental investigations into life assessment of blade-disc connections of gas turbines SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article ID CYCLIC VISCOPLASTICITY; FATIGUE AB The positively engaged connection between blade and disc of a gas turbine is highly stressed by fatigue and creep fatigue loadings. For this purpose, a new calculating method based on inelastic finite element analyses considering the main influences on damage was developed at MPA Stuttgart. Low cycle fatigue (LCF) tests with component-like specimens have been conducted for verification. Experimental data and life assessment results based on the Smith, Watson and Topper parameters were compared well. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Stuttgart, Staatl Mat Pruefungsanstalt Stuttgart, D-70569 Stuttgart, Germany. Univ Stuttgart, Dept Mat Behav, Sect Mat Laws, Staatl Mat Pruefungsanstalt Stuttgart, D-70569 Stuttgart, Germany. RP Roos, E, Univ Stuttgart, Staatl Mat Pruefungsanstalt Stuttgart, Pfaffenwaldring 32, D-70569 Stuttgart, Germany. CR CHABOCHE JL, 1989, INT J PLASTICITY, V5, P247 FATEMI A, 1998, INT J FATIGUE, V20, P9 ISSLER S, 2000, DEV EXPT VERIFICATIO MOSS S, 1997, COMMUNICATION NOUAILHAS D, 1989, INT J PLASTICITY, V5, P501 SMITH KN, 1970, J MATER, V5, P767 XU H, 1998, THESIS U STUTTGART NR 7 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD DEC PY 2003 VL 226 IS 2 BP 155 EP 164 PG 10 SC Nuclear Science & Technology GA 751FD UT ISI:000187041400007 ER PT J AU Cheruvu, NS Chan, KS Leverant, GR TI In-service degradation and life prediction of coatings for advanced land-based gas turbine buckets SO JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING LA English DT Article DE combustion turbine coatings; life prediction method; degradation mechanisms; duplex coatings; coatlife; oxidation protection; GT29+; GT33+ ID CYCLIC OXIDATION AB In-service degradation mechanisms of over-aluminized MCrAlY duplex coatings have been determined by evaluating two long-term service-run blades. Cyclic oxidation tests were also conducted to characterize the degradation of the duplex coatings, GT29+ and GT33+. The results show that degradation of duplex coatings is manifested by the formation of oxide scale, the transformation of beta-phase into gamma, the coarsening of beta-phase particles in the MCrAlY coating, and the enlargement of the interdiffusion zone. Considering all of the degradation mechanisms observed in these service-run coated buckets, a coating life prediction model, developed under an EPRI- funded program, was used to estimate the life of GT29+ and GT33+ coatings. A comparison of the model calculations and experimental data indicated that, conservatively, the useful life of duplex coatings can be predicted solely based on the Al content in the top aluminide coating. The predicted value of the coating life is increased by a factor of 1.4 to 2 if MCrAlY is included in the lifetime estimation. C1 SW Res Inst, San Antonio, TX 78238 USA. RP Cheruvu, NS, SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78238 USA. CR BARRETT CA, 1977, OXID MET, V11, P199 CHAN KS, 1997, METALL MATER TRANS A, V28, P411 CHAN KS, 1998, J ENG GAS TURB POWER, V120, P609 CHAN KS, 1999, J ENG GAS TURB POWER, V121, P484 CHAN KS, 1999, P ASME INT GAS TURB CHERUVU NS, 1996, 96GT429 CHERUVU NS, 1998, P ASME INT GAS TURB DALLIO JA, 1997, P ASME INT GAS TURB ELLISON KA, 1998, MAT ADV POWER ENG, V5, P1401 EMBLEY GT, 1985, C P LIF PRED HIGH TE, P1 SRINIVASAN V, 1995, MATER MANUF PROCESS, V10, P955 VISWANATHAN R, 1989, DAMAGE MECH LIFE ASS, P438 WALLWORK GR, 1971, OXID MET, V3, P213 WOOD WI, 1996, P ASME INT GAS TURB NR 14 TC 0 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1344-7912 J9 JSME INT J A-SOLID MECH MAT E JI JSME Int. J. Ser. A-Solid Mech. Mat. Eng. PD OCT PY 2003 VL 46 IS 4 BP 635 EP 641 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 749KC UT ISI:000186918200016 ER PT J AU Martini, P Schulz, A Whitney, CF Lutam, E TI Experimental and numerical investigation of trailing edge film cooling downstream of a slot with internal rib arrays SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Article DE trailing edge; film cooling; pressure side cutback; cooling slot; rib array AB To enhance turbine efficiency, the trailing edge thickness of stators and blades needs to be as thin as possible. One limitation on the trailing edge thickness is the requirement to cool this life-limiting region of the blade. One technique used to achieve a thin cooled trailing edge is that of a pressure side cutback with film cooling slots. There is a paucity of fluid and heat transfer data regarding this type of geometry which is currently being addressed by the EC-funded Framework V project AITEB. This paper reports on experimental work being undertaken by the University of Karlsruhe and accompanying computational fluid dynamics (CFD) calculations being performed by MTU Aero Engines and ALSTOM Power. Experimental and numerical data presented include cutback surface film cooling effectiveness together with slot discharge coefficient values. C1 Univ Karlsruhe, Inst Therm Stromungsmaschinen, D-76128 Karlsruhe, Germany. ALSTOM Power Technol Ctr, Leicester LE8 6BH, Leics, England. MTU Aero Engines GmbH, Thermodynam TPWT, Munich, Germany. RP Martini, P, Univ Karlsruhe, Inst Therm Stromungsmaschinen, Kaiserstr 12, D-76128 Karlsruhe, Germany. CR BALDAUF S, 1999, 99GT46 ASME BURNS WK, 1969, INT J HEAT MASS TRAN, V12, P935 CHOE H, 1974, 74WAHT27 ASME GOLDSTEIN RJ, 1971, ADV HEAT TRANSFER, V7, P321 GRITSCH M, 1998, THESIS KARLSRUHE TH HOLLOWAY DS, 2002, GT200230471 HOLLOWAY DS, 2002, GT200230472 ASME MARTELLETTI P, 1996, CONFIN CEPHALALGICA, V5, P3 MARTINI P, 2002, ENTWICKLUNG VERFAHRE MUKHERJEE DK, 1976, J ENG POWER, V7, P556 ROACH PE, 1987, HEAT FLUID FLOW, V8, P83 SIVASEGARAM S, 1969, J MECH ENG SCI, V7, P22 TASLIM ME, 1990, 902266 AIAA NR 13 TC 2 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0957-6509 J9 PROC INST MECH ENG A-J POWER JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PY 2003 VL 217 IS A4 BP 393 EP 401 PG 9 SC Engineering, Mechanical GA 723EM UT ISI:000185419500009 ER PT J AU Povey, T Chana, KS Jones, TV TI Heat transfer measurements on an intermediate-pressure nozzle guide vane tested in a rotating annular turbine facility, and the modifying effects of a non-uniform inlet temperature profile SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Article DE aerodynamics; heat transfer; hot streak; hot spot; inlet temperature distortion; turbomachinery vane; axial flow turbine; intermediate pressure; 1.5 turbine stages ID TURBULENCE; TRANSITION; CLOCKING; ROTOR; FLOW AB In modern gas turbine engines there exist significant temperature gradients in the combustor exit flow. These gradients arise because both fuel and dilution air are introduced within the combustor as discrete jets. The effects of this non-uniform temperature field on the aerodynamics and heat transfer rate distributions of nozzle guide vanes and turbine blades is difficult to predict, although an increased understanding of the effects of temperature gradients would enhance the accuracy of estimates of turbine component life and efficiency. Low-frequency measurements of heat transfer rate have been conducted on an annular transonic intermediate-pressure (IP) nozzle guide vane operating downstream of a high-pressure (HP) rotating turbine stage, Measurements were conducted with both uniform and non-uniform inlet temperature profiles. The non-uniform temperature profile included both radial and circumferential gradients of temperature. Experiments were conducted in the isentropic light piston facility at QinetiQ Pyestock, a short-duration engine-size turbine facility with 1.5 turbine stages, in which Mach number, Reynolds number and gas-wall temperature ratios are correctly modelled. Experimental heat transfer results are compared with predictions performed using boundary layer methods. C1 Univ Oxford, Oxford OX1 3PJ, England. QinetiQ, Farnborough, Hants, England. RP Povey, T, Univ Oxford, Parks Rd, Oxford OX1 3PJ, England. CR ABUGHANNAM BJ, 1980, J MECH ENG SCI, V22, P213 BINDER A, 1985, J ENG GAS TURB POWER, V107, P1039 BLAIR MF, 1988, 88GT125 ASME BUTLER TL, 1986, AIAA SAE ASME ASEE J CRAWFORD ME, 1976, CR2742 NASA DOORLY DJ, 1985, AGARDCPP390 DRING RP, 1982, J ENG GAS TURB POWER, V104, P729 FRASER CJ, 1994, P I MECH ENG C-J MEC, V208, P47 GOODISMAN MI, 1992, J TURBOMACH, V114, P419 HAWTHORNE WR, 1974, SECONDARY VORTICITY HILDITCH MA, 1994, 94GT277 ASME HURRION J, 2002, THESIS U OXFORD JOHNSTON DA, 1999, 99GT376 ASME JONES TV, 1995, 4 UK C HEAT TRANSF KAYS WM, 1993, MECH ENG SERIES KERREBROCK JL, 1970, T ASME KRISHNAMOORTHY V, 1989, J TURBOMACH, V111, P497 LAM CKG, 1981, J FLUIDS ENG, V103, P456 LOWERY GW, 1975, INT J HEAT MASS TRAN, V18, P1229 MOSS RW, 1993, P EUROTHERM 32 SEM, P63 MUNK M, 1947, P US NATN ACAD SCI, V33 NARASIMHA R, 1985, PROG AEROSPACE SCI, V22, P29 PARKER R, 1972, P I MECH ENG, V186 POVEY T, 2001, P IMECHE SEM ADV CFD POVEY T, 2003, ADV CFD FLUID MACHIN, P65 PRASAD D, 2000, J TURBOMACH, V122, P667 REINMOLLER U, 2002, J TURBOMACH, V124, P52 SHANG T, 1995, THESIS MIT TIEDEMANN M, 2001, J TURBOMACH, V123, P526 WITTIG S, 1985, AGARDCPP390 NR 30 TC 2 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0957-6509 J9 PROC INST MECH ENG A-J POWER JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PY 2003 VL 217 IS A4 BP 421 EP 431 PG 11 SC Engineering, Mechanical GA 723EM UT ISI:000185419500012 ER PT J AU Okazaki, M TI The potential for the improvement of high performance thermal barrier coatings SO MATERIALS SCIENCE RESEARCH INTERNATIONAL LA English DT Review DE advanced gas turbines; thermal barrier coatings (TBCs); top coat; bond coat; thermally grown oxide (TGO); electron beam physical vapor deposition (EB-PVD); thermal conductivity; micropore; control of microstructure ID BOND-COAT; SPALLING FAILURE; VAPOR-DEPOSITION; THIN-FILMS; ZIRCONIA; BEHAVIOR; ADHESION; LIFE AB The growing market for industrial gas turbines has led to an increased demand for large, cost-effective units of high efficiency, A critical issue in the development of such units is the durability of hot section components, especially first stage blades and vanes to which thermal barrier coatings (TBCs) are applied. This paper introduces the current state of the art in the production of TBCs, and discusses their various degradation mechanisms. Special emphasis is placed on the potential for the development of a new generation of TBC systems through the control of microstructure and porosity, as well as through new processing techniques. C1 Univ Tokyo, Dept Met, Bunkyo Ku, Tokyo 1138656, Japan. CR *NAT RES COUNC, 1996, COAT HIGH TEMP STRUC *ROLLS ROYC PLY, 1986, JET ENG, CH9 ANAL O, 1994, J AM CERAM SOC, V77, P984 BRANDON JR, 1991, SURF COAT TECH, V46, P75 CLARKE DR, 1997, SURF COAT TECH, V94, P89 CURTIS R, 2001, GT2001 ASME, P569 DEMASIMARCIN JT, 1990, J ENG GAS TURB POWER, V112, P521 DUET C, 1982, HIGH TEMPERATURE ALL, P53 EVANS AG, 1997, ACTA MATER, V45, P3543 EVANS AG, 1999, ACTA MATER, V47, P4093 GROVES JF, 1997, COMPOS PART B-ENG, V28, P57 GULL M, 1999, SURFACE COATING TECH, V120, P53 HARRIS KD, 2001, SURF COAT TECH, V138, P185 HAYNES JA, 2001, SCRIPTA MATER, V44, P1147 HISS DD, 1998, J VAC SCI TECH A, V16, P3396 HISS DD, 2001, ACT MAT, V49, P973 HOCKING MG, 1989, METALLIC CERAMIC COA ITOH Y, 1992, KIKAI NO KENKYU, V44, P257 JONES RL, 1996, METALLURGICAL CERAMI, P290 KOALAS MF, 1998, P ASM INT MAT, V98, P12 KYONGJUN A, 1999, J AM CERAM SOC, V82, P299 LIT W, 1991, OXIDE METALS, V3, P221 METIER SM, 1994, TRAYS ACME, V116, P250 MIGLIETTI WM, 2001, GT2001 ASME, P501 MILLER RA, 1984, J AM CERAM SOC, V67, P517 MILLER RA, 1987, SURF COAT TECH, V30, P1 MORSEL P, 1985, HIGH TEMP HIGH PRESS, V17, P79 OKADA I, 1999, GAS TURBINES, V99, P1057 OKAZAKI M, 2000, SUPERALLOYS 2000, P505 OKAZAKI M, 2002, HIGH TEMPERATURE FAT PINT BA, 1998, MAT SCI ENG A-STRUCT, V245, P201 SCHULZ U, 1996, Z METALLKD, V87, P6 SCHULZ U, 2000, J AM CERAM SOC, V83, P904 SETH BB, 2000, SUPERALLOYS 2000, P3 SHILLINGTON EAG, 1999, ACTA MATER, V47, P1297 STINGER J, 1993, P ASM 1993 MAT WEEK, P1 STINGER MJ, 2000, Z METALLKD, V90, P12 STRANGMAN TE, 1985, THIN SOLID FILMS, V127, P93 TOLPYGO VK, 2001, METALL MATER TRANS A, V32, P1467 WARNES BM, 1997, SURF COAT TECH, V94, P1 WORKMAN DJ, 1989, MAT SCI ERG A, V121, P443 WRIGHT PK, 1998, MAT SCI ENG A-STRUCT, V245, P191 ZHU DM, 1998, SURF COAT TECH, V108, P114 NR 43 TC 1 PU SOC MATERIALS SCIENCE, JAPAN PI KYOTO PA 1-101, YOSHIDA-IZUMIDONO-CHO, SAKYO-KU, KYOTO, 606-8301, JAPAN SN 1341-1683 J9 MATER SCI RES INT JI Mater. Sci. Res. Int. PD MAR PY 2003 VL 9 IS 1 BP 3 EP 8 PG 6 SC Materials Science, Multidisciplinary GA 719ZV UT ISI:000185236300002 ER PT J AU Yue, ZF Lu, ZZ TI Finite element creep damage study of nickel base single crystal structures under multiaxial stress states SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID SUPERALLOYS; MODEL AB Based on the microstructural assessment, a two state variable crystallographic creep damage constitutive equation has been presented for nickel base single crystal superalloys, which takes into consideration the rafting/derafting and damage of the voids simultaneously. With the uniaxial creep experimental data, the constitutive equation can model the creep damage behaviour of nickel base single crystal superalloys, especially the dependence of the creep anisotropy on the crystallographic orientation. The constitutive equation has been programmed as a user-subroutine UMAT into ABAQUS. Double shear specimens and modelling blades have been experimented on to validate the constitutive equation. The results of the validation were satisfactory. The damage and life behaviour of a turbine blade has been presented as an example of the application. The influence of the crystallographic orientations on the blade lives has been analysed specially for the optimisation of blade crystallographic orientations. C1 Northwestern Polytech Univ, Dept Engn Mech, Xian 710072, Peoples R China. RP Yue, ZF, Northwestern Polytech Univ, Dept Engn Mech, Xian 710072, Peoples R China. CR ARRELL DJ, 1996, SCRIPTA MATER, V35, P727 KACHANOV LM, 1958, IZV AKAD NAUK USS TN, V8, P27 KANDA M, 1997, J ENG MATER-T ASME, V119, P153 MAYR C, 1995, MAT SCI ENG A-STRUCT, V199, P121 MERIC L, 1991, J ENG MATER-T ASME, V113, P162 RABOTNOV M, 1969, CREEP PROBLEMS STRUC YIN ZY, 2001, CHIN J AERONAUTICS, V14, P18 YIN ZY, 2001, CHIN J AERONAUTICS, V14, P24 YUE ZF, 1995, METALL MATER TRANS A, V26, P1815 YUE ZF, 1999, ACTA METALL SIN, V12, P149 YUE ZF, 2001, RARE METALS ENG, V30, P221 NR 11 TC 4 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 0267-0836 J9 MATER SCI TECHNOL JI Mater. Sci. Technol. PD AUG PY 2003 VL 19 IS 8 BP 1012 EP 1016 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 717BH UT ISI:000185065400003 ER PT J AU Roy, R Tiwari, A Corbett, J TI Designing a turbine blade cooling system using a generalised regression genetic algorithm SO CIRP ANNALS-MANUFACTURING TECHNOLOGY LA English DT Article DE design; optimisation; artificial intelligence AB The design of a turbine blade cooling system is a multi-objective optimisation problem involving constraints and complex interaction among its design variables. The aim of this paper is to develop a methodology to optimise this design using Evolutionary Computing techniques. This paper presents Generalised Regression Genetic Algorithm (GRGA) and the mathematical model of a real-life turbine blade cooling system. Even in the presence of variable interaction, the methodology identifies a number of good feasible designs from which one could be finally chosen based on designer's preferences. The research also demonstrates that GRGA is capable of optimising a real-life design. C1 Cranfield Univ, Sch Ind & Mfg Sci, Cranfield MK43 0AL, Beds, England. RP Roy, R, Cranfield Univ, Sch Ind & Mfg Sci, Cranfield MK43 0AL, Beds, England. CR DEB K, 2001, MULTIOBJECTIVE OPTIM DRAPER NR, 1998, APPL REGRESSION ANAL ROY R, 1997, ADAPTIVE SEARCH PREL TAGUCHI G, 1987, SYSTEM EXPT DESIGN, V1 TIWARI A, 2001, THESIS CRANFIELD U U TIWARI A, 2002, APPL SOFT COMPUTIN F, V1, P301 NR 6 TC 1 PU TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD PI BERN PA NORDRING 4, CH-3001 BERN, SWITZERLAND J9 CIRP ANN-MANUF TECHNOL JI CIRP Ann-Manuf. Technol. PY 2003 VL 52 IS 1 BP 415 EP 418 PG 4 SC Engineering, Industrial; Engineering, Manufacturing GA 701BH UT ISI:000184145300099 ER PT J AU Starr, F TI Effects of cyclic operation on advanced energy conversion systems SO MATERIALS AT HIGH TEMPERATURES LA English DT Article DE advanced energy conversion systems; cycling; steam plant; fireside corrosion; CCGTs; recuperators; IGCCs AB The impact of plant cycling is evaluated for near and medium term advanced energy conversion systems in terms of effects on equipment and implications for the choice of materials. A brief outline is a given of current problems and their causes in steam and combined cycle gas turbine (CCGT) plants. In contrast to earlier years, it is now quite common for relatively new plants to have to cycle. The causes of this are increased competition in the power supply industry, unforeseen changes in the relative price of fuels, and regulatory changes which no longer have the effect of insulating certain types of energy conversion systems from the need to load follow and two shift. It is therefore vital that the issue of cycling be considered at the plant design stage. In advanced steam plants, where steam inlet temperatures will be well over 600degreesC, problems will involve the performance of transition joints and austenitic alloys under cycling conditions. The" R" function is described and tabulated to show the likely susceptibility of a range of ferritic, austenitic and nickel based alloys to thermal shock, caused by quenching of pipework by slugs of condensate. It would seem that even modern high strength austenitics do not have the same capability as the modified 9 and 12 Cr ferritics. There may also be problems with steam turbine materials. The main concern in advanced CCGT plants is the potential for increased thermal fatigue, due to the use of more sophisticated blade cooling techniques. However a potential issue is shortcomings in blade life assessment models as applied to directionally solidified and single crystal materials, as it seems likely that current approaches, using isotropic data, may be giving a severe over estimate. It seems unlikely that coal gasification plant will be able to two shift, although load following will be possible. It is suggested that the critical area will be that of the synthesis gas exchanger where there is potential for corrosion assisted fatigue. This problem is likely to increase if more resistant coatings are used, as these tend to be less ductile than current alloys. Conversely recuperative gas turbines are designed to load follow and two shift and should be able to resist the effects of rapid start ups and shut downs. Modern designs using either primary or secondary surface recuperators are briefly described. The topical issue here is passage collapse in primary surface systems, which is likely to increase under cycling duty. C1 European Technol Dev Ltd, Surrey, England. RP Starr, F, European Technol Dev Ltd, Surrey, England. CR 1989, HIGH TEMPERATURE STE *TURB INT, 1997, SOL MERC 59 FRESH AP ALLEN DJ, 2000, PARSONS 2000 ADV MAT, P276 ANDERSON R, 1999, RELIABILITY DURABILI, P21 BLOUGH JL, 2001, P 3 C ADV MAT TECHN, P375 BLUM R, 1994, MAT ADV POWER ENG 1, P15 BURGET W, 2000, PARSONS 2000 ADV MAT, P315 EHLERS RJ, 2001, LIFETIME MODELLING H, P78 FARRELL DM, 2000, EUROCORR 2000 FELDMULLER A, 2000, PARSONS 2000 ADV MAT, P143 FLEMING A, 1997, MAT ISSUES HEAT EXCH, P109 FLEMING A, 2002, OMMI AUG GUTTMANN V, 1997, MATER HIGH TEMP, V14, P61 HEPWORTH JK, 2001, P INT SEM CYCL OP PO HOEFT R, 2000, GE POWER SYSTEMS APR MCDONALD CF, 1997, MAT ISSUES HEAT EXCH, P337 MURAMATSU K, 1999, ADV HEAT RESISTANT S, P543 MUTTILAINEN E, 2001, BALTICA, V5, P681 NATESAN K, 1997, MAT HIGH TEMP, V14, P71 NORTON JF, 1997, MATER HIGH TEMP, V14, P81 ROHNER RR, 1997, INT C ADV STEAM PLAN, P225 SAKAI K, HITACHI REV, V47, P1 SHEPHERD DP, 2001, MATER HIGH TEMP, V18, P231 SHIBLI IA, 2001, P INT SEM CYCL OP PO SINGHEISER L, 2001, MATER HIGH TEMP, V18, P249 SKELTON P, 1987, ADV MAT TECHNOLOGY F, P359 STARR F, 2000, PARSONS 2000 ADV MAT, P459 STARR K, 2000, CALIF HIST, V79, P1 STAUBLI ME, 2000, PARSONS 2000 ADV MAT, P98 STOREY IJ, 2001, MATER HIGH TEMP, V18, P241 TOUYAMA A, 1999, ADV HEAT RESISTANT S, P495 VANLIERE J, 1997, MATER HIGH TEMP, V14, P7 VANSTONE RW, 2000, PARSONS 2000 ADV MAT, P91 WATSON ER, 19 INEC 96 I MAR ENG NR 34 TC 0 PU SCIENCE & TECHNOLOGY LETTERS PI ST ALBANS PA PO BOX 314, ST ALBANS AL1 4ZG, HERTS, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2003 VL 20 IS 1 BP 27 EP 37 PG 11 SC Materials Science, Multidisciplinary GA 697TH UT ISI:000183959000005 ER PT J AU Stanisa, B Schauperl, Z Grilec, K TI Erosion behaviour of turbine rotor blades installed in the Krsko nuclear power plant SO WEAR LA English DT Article DE erosion; steam; rotor blades; turbine ID STEAM AB Turbines installed in nuclear power plants operate with wet steam. The flow of wet steam causes the erosion of the last stage rotor blades, and can cause a considerable damage to the condensing steam turbines. This paper reviews the results of many years of monitoring and researching of the behaviour of the erosion process and its mechanism for rotor blades of 664 MW turbine installed in Krsko nuclear power plant. On the basis of the results obtained and behaviour of the erosion process, the erosion rate for rotor blades material and a simplified model for their service life is estimated. The rotor blade erosion process was divided into three characteristic regions of erosion: the first incubation region showed no evident damage to the blade material, the second region with the maximum erosion rate and the third one with the lowest erosion. It was established that the rotor blades during their service life mostly operate in the third region with a lower rate of erosion. On the basis of the obtained behaviour of the rotor blades erosion process and a simplified model and calculation their service life of 290,000 h has been estimated, which is longer than it was expected. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Fac Mech Engn & Naval Engn, Dept Mat, HR-10000 Zagreb, Croatia. Fac Tech Studies, Rijeka, Croatia. Dublin Inst Technol, Dublin, Ireland. RP Grilec, K, Fac Mech Engn & Naval Engn, Dept Mat, Ivana Lucica 5, HR-10000 Zagreb, Croatia. CR FADDEV IP, 1974, EROZIJA VLAZNOPAROVY KRZYZANOWSKI J, 1991, EROZJA LOPATEK TURBI STANISA B, 1978, STROJARSTVO, V20, P301 STANISA B, 1979, STROJARSTVO, V21, P161 STANISA B, 1987, ELEKTROPRIVREDA, V40, P357 STANISA B, 1987, P ELSI 7 CAMBR, P16 STANISA B, 1995, WEAR, V186, P395 NR 7 TC 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR PY 2003 VL 254 IS 7-8 BP 735 EP 741 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 693VY UT ISI:000183740100014 ER PT S AU Diologent, F Caron, P TI Creep behaviour at 760 degrees C of two nickel-based single crystal superalloys SO THERMEC'2003, PTS 1-5 SE MATERIALS SCIENCE FORUM LA English DT Article DE superalloy; single crystal; creep; dislocation; rhenium; AM1; MC-NG ID INTERMEDIATE TEMPERATURES; MECHANISM; STRENGTH; ALLOYS AB Creep tests have been performed at 760degreesC and 840 MPa on the AM1 and MC-NG nickel-based single crystal superalloys suited for gas turbine blade applications. The stress rupture life of MC-NG is slightly longer than that of AMI but the creep behaviours of the two alloys are very different. Clear relationships have been established between the operative deformation mechanisms and the primary creep behaviours. Occurrence of these different deformation mechanisms is discussed by taking into account the effects of various parameters such as the Orowan stress, the gamma/gamma' lattice mismatch, the stacking fault energy and the solid solution strengthening of the gamma matrix. C1 Off Natl Etud & Rech Aerosp, F-92322 Chatillon, France. RP Diologent, F, Off Natl Etud & Rech Aerosp, BP 72, F-92322 Chatillon, France. CR BUCHON A, 1991, THESIS U ROUEN FRANC CARON P, 1983, MATER SCI ENG, V61, P173 CARON P, 1985, STRENGTH METALS ALLO, P683 CARON P, 1988, SUPERALLOYS 1988, P215 CARON P, 2000, SUPERALLOYS 2000, P737 DECAMPS B, 1991, PHILOS MAG A, V64, P641 DIOLOGENT F, 2002, THESIS U PARIS 11 FR FREDHOLM A, 1987, 4639280, US GYPEN LA, 1977, J MATER SCI, V12, P1028 KAKEHI K, 2000, MAT SCI ENG A-STRUCT, V278, P135 KHAN T, 1984, SUPERALLOYS 1984, P145 LEVERANT GR, 1970, METALL T, V1, P491 MISHIMA Y, 1986, T JPN I MET, V27, P656 MURAKAMI H, 1997, MAT SCI ENG A-STRUCT, V223, P54 RAE CMF, 2002, MAT ADV POWER ENG 1, P207 ROTH HA, 1997, METALL MATER TRANS A, V28, P1329 ROYER A, 1997, SCRIPTA MATER, V36, P1151 NR 17 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2003 VL 426-4 BP 725 EP 730 PG 6 SC Materials Science, Multidisciplinary GA BW92N UT ISI:000183626400110 ER PT S AU Ardakani, MG Basoalto, H Shollock, BA McLean, M TI Characterisation and modelling of crystal rotations during multiaxial creep in single crystal superalloys SO THERMEC'2003, PTS 1-5 SE MATERIALS SCIENCE FORUM LA English DT Article DE superalloys; modeling; creep; multiaxial; anisotropic; electron backscatter diffraction (EBSD) ID BEHAVIOR AB Life prediction procedures for single crystal superalloys are largely based on the interpretation of uniaxial creep and low cycle fatigue data although turbine blades experience significant multiaxial stresses in service. Several models that have been proposed to represent the anisotropic creep of single crystal superalloys have the potential of being extended to multiaxial loading. It is appreciated that uniaxial stresses in non-symmetric orientations cause crystal rotations during creep. It is less well known that multiaxial stressing of symmetric single crystals can also lead to large crystal rotations that can be spatially heterogeneous. In this study, creep of the single crystal nickel-based superalloy CMSX-4 with <001>, <111> and <011> nominal orientations has been studied at 850degreesC on cylindrical specimens with circumferential notches and net-section stresses between 600 and 850 MPa. The predictions of crystal rotation resulting from creep deformation are compared,with the experimental results as a contribution to validating the model. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England. RP Ardakani, MG, Univ London Imperial Coll Sci Technol & Med, Dept Mat, Exhibit Rd, London SW7 2AZ, England. CR ARDAKANI MG, 1999, ACTA MATER, V47, P2593 BASOALTO HC, 2000, SUPERALLOYS 2000, P515 BRIDMAN BPW, 1952, METALLURGICAL SERIES FEDELICH B, 2002, INT J PLASTICITY, V18, P1 GHOSH RN, 1990, ACTA METALL MATER, V38, P1997 MACLACHLAN DW, 2000, METALL MATER TRANS A, V31, P1401 MERIC L, 1991, J ENG MATER-T ASME, V113, P162 SHOLLOCK BA, 1997, SCRIPTA MATER, V36, P1471 NR 8 TC 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2003 VL 426-4 BP 797 EP 802 PG 6 SC Materials Science, Multidisciplinary GA BW92N UT ISI:000183626400122 ER PT J AU Jones, K Cross, C TI On antiresonance in the forced response of mistuned bladed disks SO SHOCK AND VIBRATION LA English DT Article ID LOCALIZATION PHENOMENA; CYCLIC SYMMETRY; VIBRATIONS; FREQUENCIES; ASSEMBLIES AB Mistuning in bladed disks usually increases the forced response of the maximum responding blade leading to shortened component life in turbine engines. This paper investigates mistuning using a transfer function approach where the frequency response functions (FRFs) are described by natural frequencies and antiresonant frequencies. Using this approach, antiresonant frequencies are shown to be a critical factor in determining the maximum blade response. Two insights are gained by formulating antiresonant frequencies as the eigenvalues of reduced system matrices: 1) Mistuning a particular blade has no effect on that blade's antiresonant frequencies. 2) Engine orders N and N/2, where N is the number of blades on the disk, tend to produce the highest maximum local response. Numerical examples are given using a spring-mass-oscillator model of a bladed disk. Pole-zero loci of mistuned bladed disks show that increased maximum blade response is often due to the damping of antiresonant frequencies. An important conclusion is that antiresonant frequencies can be arranged such that a mistuned bladed disk has a lower maximum blade response than a tuned bladed disk. C1 USAF, Propuls Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Jones, K, USAF, Propuls Directorate, Res Lab, 1950 5th St, Wright Patterson AFB, OH 45433 USA. CR BREWER ME, 1999, P 1999 ASME DES ENG CASTANIER MP, 1997, P 1997 INT M ENG C E DAMBROGIO W, 2000, J SOUND VIB, V236, P227 EWINS DJ, 1969, J SOUND VIBRATION, V9, P65 JONES K, 2002, J SOUND VIB, V252, P717 KENYON JA, 2002, GT200230426 ASME LACIVITA M, 1997, P 15 INT MOD AN C, P778 LALLEMENT G, 1992, P 10 INT MOD AN C, P487 MIU DK, 1991, J DYN SYST-T ASME, V113, P419 RADE DA, 1996, P 14 INT MOD AN C, P1078 SLATER JC, 1999, SHOCK VIBRATION DIGE, V31, P17 TURCOTTE JS, 1999, P 35 AIAA ASME SAE A WAHL F, 1999, J SOUND VIB, V219, P379 WANG BP, 1998, 981751 AIAA, P431 WEI ST, 1988, J VIB ACOUST, V110, P429 WEI ST, 1988, J VIB ACOUST, V110, P439 WHITEHEAD DS, 1998, J ENG GAS TURB POWER, V120, P115 ZILL DG, 1992, ADV ENG MATH, P435 NR 18 TC 1 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1070-9622 J9 SHOCK VIBRATION JI Shock Vib. PY 2003 VL 10 IS 2 BP 135 EP 146 PG 12 SC Acoustics; Engineering, Mechanical; Mechanics GA 690LR UT ISI:000183551100006 ER PT J AU Cailletaud, G Chaboche, JL Forest, S Remy, L TI On the design of single crystal turbine blades SO REVUE DE METALLURGIE-CAHIERS D INFORMATIONS TECHNIQUES LA English DT Article AB After a short historical review, this paper recalls the successive steps of the life prediction of single crystal turbine blades, paying attention to a proper modelling of the material, to the mechanical aspects in the blades and to the boundary conditions. The code built around the FE solver ZeBuLoN is now able to predict crack initiation by post-processing of the 3D elastoviscoplastic computations. C1 Ecole Natl Super Mines, UMR CNRS 7633, Ctr Mat, Evry, France. DMSE, ONERA, Chatillon, France. RP Cailletaud, G, Ecole Natl Super Mines, UMR CNRS 7633, Ctr Mat, Evry, France. CR *SID 2 3, 1996, MAN UT BESSON J, 2001, MECANIQUE NONLINEARI CARDONA JM, 2000, THEIS ECOLE NATL SUP CHABOCHE JL, 1974, REVUE FRANCAISE MECA, V52, P37 CHABOCHE JL, 2000, THESIS U ORSAY ESPIE L, 1996, THESIS ENSMP FAHRAT C, 1994, COMPUTATIONAL MECH A, V2 FEYEL F, 1997, CR 3 C NAT CALC STRU, P309 FOERCH R, 2000, ABAQUS USER METTING FOREST S, 1996, P IUTAM S MICR PLAST, P51 FOREST S, 2000, INT J SOLIDS STRUCT, V37, P7105 GALLERNEAU F, 1995, THESIS ECOLE NATL S HANRIOT F, 1991, HIGH TEMPERATURE CON LEMAITRE J, 1990, MECH SOLID MAT LESNE PM, 1985, THESIS U LILLE MERIC L, 1991, J ENG MATER-T ASME, V113, P162 SAVALLE S, 1978, RECHERCHE AEROSPATIA, V5 NR 17 TC 0 PU REVUE DE METALLURGIE PI NANTERRE CEDEX PA LES FONTENELLES, 1 RUE DE CRAIOVA, 92024 NANTERRE CEDEX, FRANCE SN 0035-1563 J9 REV METALL-CAH INF TECH JI Rev. Metall.-Cah. Inf. Techn. PD FEB PY 2003 VL 100 IS 2 BP 165 EP 172 PG 8 SC Metallurgy & Metallurgical Engineering GA 673QG UT ISI:000182591200009 ER PT J AU Tsai, JI Lin, CH Tsao, TP TI Long-term fatigue life loss of turbine blades owing to noncharacteristic harmonic currents in asynchronous HVDC links SO ELECTRIC POWER SYSTEMS RESEARCH LA English DT Article DE HVDC; noncharacteristic harmonic; electromagnetic torque (E/M torque); torsional vibration; turbine blade; fatigue life expenditure ID GENERATOR-EXCITER SHAFTS; DC CURRENTS; TORSIONAL TORQUES; FAULTS AB The long-term effect of noncharacteristic harmonic currents in asynchronous HVDC links on fatigue life expenditure in turbine-generator blades is studied in this paper. Because the frequencies of the two main harmonic current terms are subsynchronous and offer a probability distribution due to the asynchronous operation in a HVDC link, a systematic fatigue estimation approach was devised to investigate the long-term impact for the low-pressure turbine blades. From the simulation results, it is clear that the sustained excitation of these harmonics becomes a cause of blade failure even though the harmonic current is still normal for only one generator connected to the inverter station bus. By the effect analysis of uncertainty in electrical and mechanical parameters, several schemes for the fatigue loss alleviation were then found. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. Kao Yuan Inst Technol, Dept Elect Engn, Kaohsiung 82101, Taiwan. RP Tsao, TP, Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. CR *IEEE SSR WORK GRO, 1991, IEEE T PAS, P830 ARRILLAGA J, 1983, HIGH VOLTAGE DIRECT CHYN C, 1996, IEE P-GENER TRANSM D, V143, P479 CUDWORTH CJ, 1990, IEE PROC-C, V137, P327 FARIED SO, 1996, IEE P-GENER TRANSM D, V143, P487 FARIED SO, 1997, IEEE T POWER SYST, V12, P875 GONZALEZ AJ, 1984, IEEE T POWER AP SYST, V103, P3218 HAMMONS TJ, 1980, IEEE T PAS, V99, P1652 HAMMONS TJ, 1994, IEEE T ENERGY CONVER, V9, P503 HAMMONS TJ, 1995, IEEE T ENERGY CONVER, V10, P95 HAMMONS TJ, 1995, IEEE T POWER SYST, V10, P1572 HAMMONS TJ, 1997, ELECTR MACH POW SYST, V25, P87 LIN CH, 2001, IEE P GENER TRANSM D, V148 MASRUR MA, 1991, IEE P C, V138, P4756 PLACEK RJ, 1984, EL3083 EPRI SHI W, 1994, IEEE T POWER SYST, V9, P1457 TSAO TP, 2000, IEE P SCI MEAS TECHN, V147 WILLIAMS RA, 1986, IEEE T ENERGY CONVER, V1, P80 YACAMINI R, 1986, IEE PROC-C, V133, P301 NR 19 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7796 J9 ELEC POWER SYST RES JI Electr. Power Syst. Res. PD MAY PY 2003 VL 65 IS 2 BP 135 EP 147 PG 13 SC Engineering, Electrical & Electronic GA 672DK UT ISI:000182505700007 ER PT J AU Boyce, BL Chen, X Peters, JO Hutchinson, JW Ritchie, RO TI Mechanical relaxation of localized residual stresses associated with foreign object damage SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE titanium; Ti-6Al-4V; foreign-object damage; impact; residual stress; X-ray diffraction; fatigue ID HIGH-CYCLE FATIGUE; AISI-4140 STEEL; TI-6AL-4V; LIFE AB Foreign-object damage associated with the ingestion of debris into aircraft turbine engines can lead to a marked degradation in the high-cycle fatigue (HCF) life of turbine components. This degradation is generally considered to be associated with the premature initiation of fatigue cracks at or near the damage sites-, this is suspected to be due to, at least in part, the impact-induced residual stress state, which can be strongly tensile in these locations. However, recent experimental studies have shown the unexpected propensity for impact-induced fatigue crack formation at locations of compressive residual stress in the vicinity of the impact site. To address this issue, in situ and ex situ spatially-re solved X-ray diffraction and numerical modeling are utilized to show that the initial residual stress state can be strongly relaxed during the fatigue loading process. The magnitude and rate of relaxation is strongly dependent on the applied loads. For a Ti-6Al-4V turbine blade alloy, little relaxation was observed for an applied maximum stress of 325 MPa (0.35sigma(y), where sigma(y) is the yield stress), and cracks tended to form in subsurface zones of tensile residual stress away from the damage sites. In contrast, at an applied maximum stress of 500 MPa (0.54sigma(y)), equal to the smooth-bar 10(7)- cycle endurance strength, cracks tended to form at the damage sites in zones of high stress concentration that had initially been in strong compression, but had relaxed during the fatigue loading. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Div Mat Sci, Lawrence Berkeley Natl Lab, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Boyce, BL, Sandia Natl Labs, POB 5800,MS 0889, Albuquerque, NM 87185 USA. CR *HIBB KARLSS SOR I, 1998, ABAQUS VERS 5 7 US M ALTENBERG I, 1999, SURFACE TREATMENT 4 BOYCE BL, 2001, MECH MATER, V33, P441 CHEN X, 2001, INT J FATIGUE, V107, P31 EYLON D, 1998, SUMMARY AVAILABLE IN HOLZAPFEL H, 1998, MAT SCI ENG A-STRUCT, V248, P9 HUDAK SJ, 1999, HIGH CYCLE FATIGUE T JAMES MR, 1983, SCRIPTA METALL, V17, P1101 KITAGAWA H, 1976, P 2 INT C MECH BEH M, P627 MCCLINTON M, 1982, MATER SCI ENG, V56, P259 MORRIS WL, 1982, J MATER SCI, V17, P1413 NICHOLAS T, 1999, INT J FATIGUE S, V21, S221 NOYAN IC, 1987, RESIDUAL STRESS MANA PETERS JO, 2000, ENG FRACT MECH, V67, P193 PETERS JO, 2001, INT J FATIGUE S, V23, S413 PETERS JO, 2002, ENG FRACT MECH, V69, P1425 PREVEY PS, 1977, ADV XRAY ANAL, V20, P345 RUSCHAU JJ, 2001, INT J IMPACT ENG, V25, P233 SRIDHAR BR, 1996, J MATER SCI, V31, P4381 WAGNER L, 1984, P 2 INT C SHOT PEEN, P306 WICK A, 2000, MAT SCI ENG A-STRUCT, V293, P191 NR 21 TC 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAY 25 PY 2003 VL 349 IS 1-2 BP 48 EP 58 PG 11 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 668HK UT ISI:000182284100006 ER PT J AU Pascal, C Marin-Ayral, RM Tedenac, JC Merlet, C TI Combustion synthesis: a new route for repair of gas turbine components - achievements and perspectives for development of SHS rebuilding SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article DE hot isostatic pressing; self-propagating high-temperature synthesis; intermetallics; superalloys; joining; repair AB Repair techniques such as brazing diffusion remetalling (BDR) are extensively and successfully used in the aeronautical industry to extend the life of damaged turbine blades. Nevertheless, the development of new repair processes able to generate a reduction of costs and/or of the duration of the treatment cycles is a permanent objective. The basic advantages of the repair process based on the self-propagating high-temperature synthesis (SHS) are the rapidity, the self-generation of energy, the local treatment of the turbine component and the reduction in temperature by turbine component. This process ensures similar mechanical properties as traditional processes or at least sufficient for some applications. The purpose of this paper is to explain the principle of the SHS build-up process and through some examples to show the possibilities and the economical advantages offered. The build-up of a turbine blade tip and the simultaneous synthesis and joining of a NiCrAlY layer to a superalloy substrate are described. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Montpellier 2, UMR5617, LPMC, F-34095 Montpellier, France. Univ Montpellier 2, ISTEEM, F-34095 Montpellier, France. RP Marin-Ayral, RM, Univ Montpellier 2, UMR5617, LPMC, Pl Eugene Bataillon, F-34095 Montpellier, France. EM ayral@lpmc.univ-montp2.fr CR DEMASIMARCIN JT, 1994, SURF COAT TECH, V68, P1 DUMEZ MC, 1996, 9610351, FR DUVALL DS, 1974, WELD J, V53, P203 HERMANEK FJ, 1984, 840820 SOC AUT ENG HONNORAT Y, 1982, P AG C CP 31M HOPPIN GS, 1970, WELD J, V11, S505 IKAWA H, 1977, T JPN WELD SOC, V8, P3 LASALMONIE A, 1987, ANN CHIM FRANCAISES, V12, P247 LESCOURGUES J, 1985, P AGARD SPEC M OB MARIJNISSEN GH, 1987, P 17 INT C COMB ENG, P1 MATTHEIJ JHG, 1985, MAT SCI TECHNOL, V1, P608 MERZHANOV AG, 1997, RUSS CHEM B+, V46, P1 MUNIR ZA, 1988, CERAM B, V2, P342 MUNIR ZA, 1989, MAT SCI REP, V3 PASCAL C, UNPUB COMBUSTION SYN PASCAL C, UNPUB SIMULTANEOUS S SHIRZADI AA, 1997, 9610351, FR SHIRZADI AA, 1997, 97091672, UK SHIRZADI AA, 1997, SCI TECHNOL WELD JOI, V2, P89 VANSCHAIK T, 1983, MODERN POWER SYST, V3, P29 VILNAT M, 1986, USINE NOUVELLE, V6, P67 NR 21 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECHNOL JI J. Mater. Process. Technol. PD APR 1 PY 2003 VL 135 IS 1 BP 91 EP 100 PG 10 SC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary GA 659ZL UT ISI:000181809300010 ER PT J AU Hermanson, K Kern, S Picker, G Parneix, S TI Predictions of external heat transfer for turbine vanes and blades with secondary flowfields SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article ID BOUNDARY-LAYERS; MODEL; ENDWALL; REGION AB Detailed heat transfer distributions on the endwall and along the vane/blade surface are essential for component mechanical integrity and life predictions. Due to secondary flows, high gradients in heat transfer are present at the endwall and at the vane or blade surface itself where the passage vortex influences the mainstream flow This paper documents the benchmarking of three turbulence models: 1) k-epsilon realizable with wall functions, 2) k-epsilon realizable with two layer model, and 3) the V2F model for endwall and surface heat transfer and flowfield predictions. Benchmark experimental data from a scaled-up low speed rig for both a stator and rotor geometry are used for comparisons of heat transfer and flowfield. While the k-epsilon realizable turbulence models give a good prediction of the secondary flow pattern, the heat transfer at the endwall and at the surface is not well predicted due to the inadequate modeling of near wall turbulence. The V2F model gives better agreement with the experiments on the endwall and vane midspan heat transfer is also well predicted, although transition occurs too,far upstream on the suction surface. The results from this study represent the feasibility of CFD utilization as a predictive tool for local heat transfer distributions on a vane/blade endwall. C1 Alstom Power Switzerland, CH-5401 Baden, Switzerland. RP Hermanson, K, Alstom Power Switzerland, CH-5401 Baden, Switzerland. CR *FLUENT INC, 1999, FLUENT US GUID VERS BOYLE RJ, 2001, ANN NY ACAD SCI, V932, P11 CHIMA RV, 1993, 930083 AIAA CHO HH, 2001, ANN NY ACAD SCI, V934, P281 CRAWFORD ME, 1986, LECT SERIES VONKARMA DURBIN PA, 1991, THEOR COMP FLUID DYN, V3, P1 DURBIN PA, 1993, INT J HEAT FLUID FL, V14, P316 GIEL PW, 1999, 99GT125 ASME GOLDSTEIN RJ, 1988, J HEAT TRANS-T ASME, V110, P862 GRAZIANI RA, 1980, ASME, V102, P257 HERMANSON K, 1999, AIAA POWER TURBOMACH, V16, P286 HERMANSON K, 1999, THESIS U WISCONSIN M HERMANSON K, 2001, ANN NY ACAD SCI, V932, P448 KANG M, 1998, THESIS U WISCONSIN M KANG M, 2000, ASME, V122, P458 KANG MB, 1999, J TURBOMACH, V121, P558 KHAWAJA A, 1999, 990916 AIAA LANGSTON LS, 1980, ASME, V109, P186 LAUNDER BE, 1974, COMPUTER METHODS APP, V3, P269 PARNEIX S, 1998, FLOW TURBUL COMBUST, V60, P19 RADOMSKY R, 2000, ASME, V122, P255 SHARMA OP, 1987, ASME, V109, P229 SHIH TH, 1995, COMPUT FLUIDS, V24, P227 SIEVERDING CH, 1985, ASME, V107, P248 WALTERS DK, 2000, J TURBOMACH, V122, P537 NR 25 TC 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD JAN PY 2003 VL 125 IS 1 BP 107 EP 113 PG 7 SC Engineering, Mechanical GA 643AU UT ISI:000180840400013 ER PT J AU Lee, BE Riu, KJ Shin, SH Kwon, SB TI Development of a water droplet erosion model for large steam turbine blades SO KSME INTERNATIONAL JOURNAL LA English DT Article DE water droplet erosion; steam turbine blade ID TI-6AL-4V AB Water droplet erosion is one of major concerns in the design of modern large fossil steam turbines because it causes serious operational problems such as performance degradation and reduction of service life. A new erosion model has been developed in the present study for the prediction of water droplet erosion of rotor blades operated in wet steam conditions. The major four erosion parameter; impact velocity, impacting droplet flow rate, droplet size and hardness of target are involved in the model so that it can also be used for engineering purpose at the design stage of rotor blades. Comparison of the predicted erosion rate with the measured data obtained from the practical steam turbine operated for more than 90,000 hours shows good agreement. C1 Korea Aviat Polytech Coll, Dept Aeronaut Engn, Sachon 664180, Kyungnam, South Korea. Kyungpook Natl Univ, Coll Engn, Sch Mech Engn, Taegu 702701, South Korea. RP Lee, BE, Korea Aviat Polytech Coll, Dept Aeronaut Engn, 438 Egeum Dong, Sachon 664180, Kyungnam, South Korea. CR ADLER WF, 1995, WEAR, V186, P35 DRAHY J, 1988, P EPRI WORKSH TIT ST, P405 FIELD JE, 1999, WEAR, V233, P1 GELFAND BE, 1996, PROG ENERG COMBUST, V22, P201 GERDES C, 1995, WEAR, V186, P368 KRZYANOWSKI JA, 1994, J ENG GAS TURB POWER, V116, P442 KRZYZANOWSKI J, 1978, ASME, V100, P561 LEYZEROVICH A, 1997, LARGE POWER STEAM TU OEYNHAUSEN H, 1993, P AM POW C CHIC ILL, P1 ROBINSON JM, 1995, WEAR, V186, P360 RUML Z, 1995, WEAR, V186, P421 SCHOFIELD P, 1997, GER3750C GE POW SYST STANISA B, 1995, WEAR, V186, P395 TSUBOUCHI K, 1990, PRESSURIZED WATER RE, V10, P245 NR 14 TC 1 PU KOREAN SOC MECHANICAL ENGINEERS PI SEOUL PA KSTC NEW BLD. 7TH FLOOR, 635-4 YEOGSAM-DONG KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 1226-4865 J9 KSME INT J JI KSME Int. J. PD JAN PY 2003 VL 17 IS 1 BP 114 EP 121 PG 8 SC Engineering, Mechanical GA 633JC UT ISI:000180278400013 ER PT J AU Zheng, YR Han, YF TI Cost considerations of single crystal superalloys for gas turbine SO ACTA METALLURGICA SINICA LA Chinese DT Article DE single crystal superalloy; cost consideration; structural stability; service life ID SOLIDIFICATION AB The cost considerations during the development and application of single crystal (SC) superalloys have been described in this paper. The partial substitution of Ru for Re can increase the long term microstructure stability of the SC superalloy and lower their cost significantly. The addition of C, B and Hf can improve the castability of the alloy, and hence increase the yield of blade production. Re-solution treatment can prolong the service life of the SC superalloys effectively. The use of computer materials design will shorten the development period of the alloy. The use of revert materials can decrease the cost, economize resource and meet the requirement of environment protection. C1 Inst Aeronaut Mat, Sci & Tech Comm, Beijing 100095, Peoples R China. RP Zheng, YR, Inst Aeronaut Mat, Sci & Tech Comm, Beijing 100095, Peoples R China. CR ARGENCE D, 2000, SUPERALLOYS 2000, P829 BOTTGER B, 2000, SUPERALLOYS 2000, P313 CHEN ZQ, 1998, THESIS BEIJING I AER DAROLIA R, 1988, SUPERALLOYS 1988, P255 DUHL DN, 1991, ALLOY PHASE STABILIT, P186 ERICKSON GL, 1996, SUPERALLOYS 1996, P35 ERICKSON GL, 1996, SUPERALLOYS 1996, P45 GOULETTE MJ, 1996, SUPERALLOYS 1996, P3 HARADA H, 2001, 2 INT S HIGH TEMP MA, P4 HINO T, 2000, SUPERALLOYS 2000, P729 KOIZUMI Y, 1997, ADV TURBINE MAT DESI, P679 KOIZUMI Y, 1998, MAT ADV POWER ENG 19UNSP P.2-1089 KOIZUMI Y, 2001, 2 INT S HIGH TEMP MA, P30 KRAFT S, 1995, SCRIPTA METALL MATER, V32, P411 MULLER L, 1992, ACTA METALL MATER, V40, P1321 MURAKAMI H, 2000, SUPERALLOYS 2000, P747 MURAKUMO T, 2001, 2 INT S HIGH TEMP MA, P18 MURATA Y, 2000, SUPERALLOYS 2000, P285 MURPHY WH, 1997, 5695821, US NABARRO FRN, 1996, METALL MATER TRANS A, V27, P513 PESSAH M, 1992, SUPERALLOYS 1992, P567 POLLOCK TM, 1992, ACTA METALL MATER, V40, P1 POLLOCK TM, 1995, MAT SCI ENG B-SOLID, V32, P255 POLLOCK TM, 1996, METALL MATER TRANS A, V27, P1081 ROSS EW, 1996, SUPERALLOYS 1996, P19 SCHAEFFER JC, 1994, 5334263, US SCHNEIDER MC, 1997, METALL MATER TRANS A, V28, P1517 SETH BB, 2000, SUPERALLOYS 2000, P3 SHAH DM, 2000, SUPERALLOYS 2000, P295 SIMONETTI M, 1998, MAT SCI ENG A-STRUCT, V254, P1 TAMAKI H, 2001, 2 INT S HIGH TEMP MA, P34 TETALAFF U, 2000, SUPERALLOYS 2000, P273 TIN S, 2000, SUPERALLOYS 2000, P201 WALSTON WS, 1995, 5455120, US WALSTON WS, 1996, SUPERALLOYS 1996, P9 WALSTON WS, 1999, LONG TERM STABILITY, P43 XUAN ND, 1990, 4935072, US YUKAWA N, 1988, SUPERALLOYS 1988, P225 ZHENG YR, 2000, SUPERALLOYS 2000, P305 NR 39 TC 0 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0412-1961 J9 ACTA METALL SIN JI Acta Metall. Sin. PD NOV PY 2002 VL 38 IS 11 BP 1203 EP 1209 PG 7 SC Metallurgy & Metallurgical Engineering GA 625QV UT ISI:000179827800014 ER PT J AU Nijssen, RPL van Delft, DRV van Wingerde, AM TI Alternative fatigue lifetime prediction formulations for variable-amplitude loading SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID DAMAGE AB Accurate prediction of lifetime is an increasingly important issue for wind turbine rotor blade materials. Coupon tests with the variable-amplitude standard loading sequences for wind turbines known as WISPER and WISPERX have indicated that the coupon lifetime can be overestimated by one or two orders of magnitude using conventional lifetime prediction formulations. In the actual design, this might be compensated for by conservative design factors covering other aspects such as environmental conditions. These conventional lifetime prediction formulations use Rainflow counting of the load history, a log-log SN-curve (stress- or strain amplitude versus cycles to failure) for R = -1, a linear Goodman diagram as a constant-life diagram, and Miner summation. In this work, possible alternative fatigue formulations to improve lifetime prediction under variable-amplitude loading are investigated. Results of WISPER and WISPERX variable-amplitude tests on a material representative of wind turbine rotor blades are used. Only alternatives for the SN-curve and the constant-life diagram are investigated; Rainflow counting and Miner summation are used in all predictions discussed here. None of the investigated SN-curves unites an apparent correlation of constant-amplitude data with an accurate and/or conservative lifetime prediction, when including them in a classical linear Goodman diagram. However, the lin-log- and log-log SN-curves do yield better predictions in combination with an alternative constant-life diagram. C1 Delft Univ Technol, WMC Grp, Delft, Netherlands. RP Nijssen, RPL, Delft Univ Technol, WMC Grp, Delft, Netherlands. CR BACH PW, 1992, C92072 ECN PETT BACH PW, 1994, C9420 ECN BOND IP, 1999, COMPOS PART A-APPL S, V30, P961 DEJONGE JB, 1983, AGARDOGRAPH, V292, P91 ECHTERMEYER AT, 1996, P EUR WIND EN C, P907 GAMSTEDT EK, 2001, R1261 RIS GERMANISCHER L, 1993, RULES REGULATION 4 1 KENSCHE CW, 1996, FATIGUE MAT COMPONEN LAVOIR JA, 2000, INT J FATIGUE, V22, P467 LEE LJ, 1996, COMPOS SCI TECHNOL, V56, P635 MANDELL JF, 1997, SAND973002 SAND NAT MOREL F, 2000, INT J FATIGUE, V22, P101 RINK HD, 1995, 69430 STEV SUBRAMANIAN S, 1995, INT J FATIGUE, V17, P343 SUTHERLAND HJ, 1999, SAND990089 SAND NAT SUTHERLAND HJ, 2000, P ASME AIAA WIND EN, P413 TENHAVE AA, 1988, P EUR COMM WIND EN C, P448 TENHAVE AA, 1992, 91476 NLR TP U TENHAVE AA, 1993, 12 ASME WIND EN S NA VANDELFT DRV, 1996, 69620 STEV VANDELFT DRV, 1997, AIAA WIND EN S WAHL NK, 2001, THESIS MONTANA STATE NR 22 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2002 VL 124 IS 4 BP 396 EP 403 PG 8 SC Energy & Fuels; Engineering, Mechanical GA 618FL UT ISI:000179408000010 ER PT J AU Sondak, DL Gupta, V Orkwis, PD Dorney, DJ TI Effects of blade count on linearized and nonlinear hot streak clocking simulations SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID TURBINE STAGE AB The temperature field exiting gas turbine combustors is highly nonuniform due to streaks of hot fluid directly downstream of combustor fuel nozzles. These hot streaks have been shown to limit the life of turbine blades. Adjusting the positions of hot streaks with respect to nozzle guide vanes, known as hot streak clocking, can be used to help control blade temperatures in gas turbines. Because hot streak clocking predictions require unsteady, three-dimensional simulations, they are very expensive, and various techniques are used to reduce their cost. Two of these techiques are examined, linearized Navier-Stokes solvers and reduced-blade-count simulations. Hot streak clocking simulations have been performed using nonlinear and linearized Navier-Stokes solvers for 1-1-1 and 3-4-3 blade-count (blades per row) configurations. The blade-count effects were examined for each solution technique, and the two solution techniques were compared. It is shown that the linearized technique can be used to capture qualitatively hot streak clocking effects. It is also shown that the reduced-blade-count approximation has a significant impact on predicted surface temperatures. C1 Boston Univ, Off Informat Technol, Boston, MA 02215 USA. Univ Cincinnati, Dept Aerosp Engn, Cincinnati, OH 45221 USA. NASA, George C Marshall Space Flight Ctr, Appl Fluid Dynam Grp, Huntsville, AL 35812 USA. RP Sondak, DL, Boston Univ, Off Informat Technol, Boston, MA 02215 USA. CR ADAMCZYK JJ, 1985, 85GT226 ASME BALDWIN BS, 1978, 78257 AIAA BUSBY J, 2000, J TURBOMACH, V122, P62 BUTLER TL, 1989, J PROPUL POWER, V5, P64 DILS RR, 1979, 561 NAT BUR STAND DORNEY DJ, 1992, J PROPUL POWER, V8, P520 DORNEY DJ, 1996, J PROPUL POWER, V12, P619 DRING RP, 1986, 4079 NASA CR GUNDYBURLET K, 1997, INT J TURBO JET ENG, V14, P133 HOLMES DG, 1997, UNSTEADY AERODYNAMIC, P221 KERREBROCK JL, 1970, ASME T A, V92, P359 KROUTHEN B, 1990, J PROPULSION POWER, V6, P769 MUNK M, 1947, P NATL ACAD SCI USA, V33, P137 ORKWIS PD, 2000, 2000GT0509 ASME ROBACK RJ, 1993, J TURBOMACH, V115, P657 ROE PL, 1981, J COMP PHYSIOL, V43, P357 ROE PL, 1981, J COMPUT PHYS, V43, P372 SHANG T, 1997, J TURBOMACH, V119, P544 SONDAK DL, 1996, 962570 AIAA TAKAHASHI RK, 1996, 962796 AIAA NR 20 TC 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 2002 VL 18 IS 6 BP 1273 EP 1279 PG 7 SC Engineering, Aerospace GA 617UT UT ISI:000179379800018 ER PT J AU Abdul-Aziz, A TI Assessment of crack growth in a space shuttle main engine first-stage high-pressure fuel turbopump blade SO FINITE ELEMENTS IN ANALYSIS AND DESIGN LA English DT Article AB A two-dimensional finite element fracture mechanics analysis of a space shuttle main engine (SSME) turbine blade firtree was performed using the MARC finite element code. The analysis was conducted under combined effects of thermal and mechanical loads at steady-state conditions. Data from a typical engine stand cycle of the SSME engine were used to run a heat transfer analysis and, subsequently, a thermal structural fracture mechanics analysis. Temperature and stress contours for the firtree under these operating conditions were generated. High stresses were found at the firtree lobes where crack initiation was triggered. A life assessment of the firtree was done by assuming an initial and a final crack size. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Cleveland State Univ, NASA, Glenn Res Ctr, Dept Civil & Environm Engn, Cleveland, OH 44135 USA. RP Abdul-Aziz, A, Cleveland State Univ, NASA, Glenn Res Ctr, Dept Civil & Environm Engn, 21000 Brook Pk Rd,MS 6-1, Cleveland, OH 44135 USA. CR *MACN CORP, 1997, MSC PATRAN GRAPH FIN, V1 *MACN CORP, 1997, MSC PATRAN GRAPH FIN, V2 *MARC RES AN CORP, 1996, MARC FIN EL COD US I, A *MARC RES AN CORP, 1996, MARC FIN EL COD US I, C *ROCKW INT CORP RO, 1987, MAT PROP AMN *ROCKW INT, 1987, SSME TURB BLAD AN TE BARSOUM RS, 1976, INT J NUMER METH ENG, V10, P25 LEE H, 1988, TM100327 NASA NAGTEGAAL JC, 1981, INT J NUMER METH ENG, V17, P15 PARIS PC, 1963, J BASIC ENG, V85, P528 RICE JR, 1973, P S NUM COMP METH ST, P585 NR 11 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-874X J9 FINITE ELEM ANAL DESIGN JI Finite Elem. Anal. Des. PD NOV PY 2002 VL 39 IS 1 BP 1 EP 15 PG 15 SC Mathematics, Applied; Mechanics GA 609VB UT ISI:000178924300001 ER PT S AU Kim, I Dost, S King, HW Ferguson, S Nagy, DR TI Relationships between the texture and longevity of TiN thin films SO TEXTURES OF MATERIALS, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article DE corrosion; dense structure; erosion; longevity; pinholes; texture; TiN; wear ID LIQUID IMPACT EROSION; CORROSION AB TiN thin films are widely used as a coating material, due to their good mechanical and conductivity properties, high thermal properties, strong wear, erosion, and corrosion resistance. In spite of these good mechanical properties, turbine blades always fail during use. The corrosion resistance of the TiN coatings is increased by a uniform and dense structure. One researcher determined that, for TiN ion plated ornaments, it was good to have uniform and dense structure which was (200) texture, and bad to have an open columnar structure which was (111) texture. Another researcher suggested that TiN films with a strong (111) orientation have better wear resistance. Thus, the longevity of TiN coated parts is related to the texture of the TiN layer that coats them, and, most importantly, to the microstructure of the TiN layer. As well as texture, the corrosion of TiN thin films was related to pinhole densities. Defects such as pinholes or cracks expose the less noble substrate underneath to a corrosive ambient. The microstructure of these thin films is also different when produced under various processing conditions. In this paper, we review and study the relationships between texture and longevity of TiN thin films. The flatness of (012) texture surface of TiN thin films is flatter than that of (111) texture surface. The longevity of TiN coated products is influenced by the properties of wear, erosion, and corrosion resistance of TiN thin films, which in turn, are related to their texture, pinhole densities, density of structure, and surface flatness. C1 Kum Oh Natl Univ Technol, Sch Adv Mat & Syst Engn, Kumi 730701, Kyung Buk, South Korea. Univ Victoria, Dept Mech Engn, Victoria, BC V8W 3P6, Canada. Liburdi Engn Ltd, Dundas, ON L9H 7K4, Canada. RP Kim, I, Kum Oh Natl Univ Technol, Sch Adv Mat & Syst Engn, Kumi 730701, Kyung Buk, South Korea. CR KOBAYASHI M, 1978, THIN SOLID FILMS, V54, P67 KOBAYASHI M, 1981, 2075068, GB, APPL KORHONEN AS, 1994, VACUUM, V45, P1031 LEE DN, 1999, J MATER SCI, V34, P2575 LEE MK, 1998, J NUCL MATER, V257, P134 LEE MK, 1999, METALL MATER TRANS A, V30, P961 MATTHEWS A, 1983, P I ION ENG C KYOT S, P1325 MEHERHOMJI CB, 1995, POWER DEC, P35 MONTOJIMA S, 1986, THIN SOLID FILMS, V137, P59 MOVECHAN BA, 1969, PHYS MET METALLOGR, V28, P83 NAGY DR, 1994, P PROP EN PAN PEP S, P27 NISHIDA N, 1980, 4226082, US PARAMESWARAN VR, 1992, SURF COAT TECH, V52, P251 RICKERBY DS, 1989, SURF COAT TECH, V39, P397 SUE JA, 1987, SURF COAT TECH, V33, P169 THRONTON JA, 1974, J VAC SCI TECHNOL, V11, P666 THRONTON JA, 1975, J VAC SCI TECHNOL, V12, P830 YILBAS BS, 1995, COMPUTER METHODS EXP, V2, P129 YILBAS BS, 1995, CORROS SCI, V37, P1627 NR 19 TC 3 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2002 VL 408-4 BP 1585 EP 1590 PG 6 SC Materials Science, Multidisciplinary GA BV22J UT ISI:000178202200253 ER PT J AU Sakuma, A Takahashi, T Fujiwara, T Fukuda, M TI Upgrading and life extension technologies for existing steam turbines SO JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING LA English DT Article DE steam turbine; upgrading; life extension AB The improvement of efficiency has been one of the most significant aspects of the development and application of steam turbines, along with the improvement of reliability and gains in both reduced maintenance and extended operation. There is now extra emphasis on evolving increased efficiency, because of the environmental need to reduce the problem of carbon dioxide. On the other hand, a lot of the existing steam turbines which were designed and manufactured based on conventional production technologies of those days are now still operating, and the most units have been utilized for more than ten or twenty years, because recently the construction of new power generation plants has been restricted. And furthermore, in some aging existing steam turbines, the decreased performance, efficiency and availability have been discovered due to time deterioration of the turbine parts and components. Under these circumstances, upgrading and life extension for the performance and reliability of steam turbines is required particularly for the existing ones((1)-(3)). This paper describes the recent development and application of advanced steam path design, such as nozzles and blades for improving performance and reliability, that is, the upgrading and life extension of existing steam turbines as well as new projects. And also it describes a repowering system for existing power plants using gas turbines. These components and technologies are applicable to both new and retrofitted units. C1 Toshiba Co Ltd, Tsurumi Ku, Yokohama, Kanagawa 2300045, Japan. RP Sakuma, A, Toshiba Co Ltd, Tsurumi Ku, 2-14 Suehiro Cho, Yokohama, Kanagawa 2300045, Japan. CR KAKISHIMA M, 1997, NEWLY DEV LOW PRESSU, P1454 KURIYAMA R, 1991, DEV HIGH EFFICIENCY, P870 OHARA H, 1995, TECHNICAL FEATURES O, P1121 SAKUMA A, 1998, NEWLY DEV COMPONENTS, P14 SUZUKI A, 1985, EFFICIENCY IMPROVEME, P916 NR 5 TC 1 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1340-8054 J9 JSME INT J SER B JI JSME Int. J. Ser. B-Fluids Therm. Eng. PD AUG PY 2002 VL 45 IS 3 BP 492 EP 498 PG 7 SC Thermodynamics; Engineering, Mechanical GA 598RP UT ISI:000178290500009 ER PT J AU Eaton, HE Linsey, GD TI Accelerated oxidation of SiCCMC's by water vapor and protection via environmental barrier coating approach SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article DE composites; corrosion; engine components; environmental barrier coating; SiC ID SIO2 SCALE VOLATILITY; COMBUSTION CONDITIONS; RECESSION; MODEL AB Silicon carbide fiber reinforced silicon carbide matrix composites (SiC/SiC CMC's) are attractive materials for use in gas turbine hot sections due to the potential for high temperature mechanical properties and overall lower density than metals. Potential SiC/SiC CIVIC gas turbine components include combustion liners, and turbine shrouds, vanes, and blades. Engine design with SiC/SiC CMC's will allow optimization for performance, efficiency, and/or emissions. However, SiC/SiC CMC's are silica formers under oxidizing conditions and have been shown experimentally to undergo accelerated oxidation due to exposure to steam in high temperature combustion environments such as found in the gas turbine hot section. Oxidation by steam in a flowing gas stream has been shown to exhibit paralinear behavior and result in unacceptable recession of the surface. Thus, prior to the successful introduction of SiC/SiC CMC's for long life use in gas turbines, the problem of accelerated oxidation needs to be addressed and resolved. To this end, one approach has been the development of the environmental barrier coating (EBC) to prevent accelerated oxidation by limiting oxidant access to the surface of the silica former. This paper will review the accelerated oxidation of silica formers such as silicon carbide, the experimental testing confirming the problem, and EBC approaches resolving the problem. (C) 2002 Published by Elsevier Science Ltd. C1 United Technol Res Ctr, E Hartford, CT 06108 USA. RP Eaton, HE, United Technol Res Ctr, 411 Silver Lane, E Hartford, CT 06108 USA. CR 1044943, EP, APPL 6254935, US 6284325, US 6296941, US CORMAN G, 2001, 2001GT593 ASME EATON HE, 2000, 2000GT631 ASME EATON HE, 2000, 24 ANN C CER MET CAR EATON HE, 2001, 2001GT513 ASME ELDRIDGE JI, 2001, CERAM ENG SCI PROC, V22, P383 FERBER MK, 2000, 2000GT661 ASME FILSINGER D, 1999, 1999GT349 ASME LEA AC, 1949, J SOC GLASS TECH, V33, T27 LEE KN, 2000, SURF COAT TECH, V133, P1 MIRIYALA N, 2001, 2001GT512 ASME MORE KL, 2000, J AM CERAM SOC, V83, P211 OPILA EJ, 1997, J AM CERAM SOC, V80, P1009 OPILA EJ, 1997, J AM CERAM SOC, V80, P197 OPILA EJ, 1999, J AM CERAM SOC, V82, P1826 ROBINSON RC, 1999, J AM CERAM SOC, V82, P1817 SCHENK BJ, 2001, 2001GT459 ASME SMIALEK JL, 1999, ADV COMPOS MATER, V8, P33 WENGLARZ RA, 2000, 2000GT73 ASME YURI I, 2000, 2000GT664 ASME NR 23 TC 13 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2741 EP 2747 PG 7 SC Materials Science, Ceramics GA 597ZZ UT ISI:000178251800040 ER PT J AU Kubiak, JA Urquiza-Beltran, G TI Simulation of the effect of scale deposition on a geothermal turbine SO GEOTHERMICS LA English DT Article DE geothermal turbine; efficiency; steam path deterioration; scale; power utility AB Dissolved chemicals contained in geothermal steam can lead to corrosion, erosion and deposition of scale on turbine blades, reducing their useful life. In addition, deposits on the blading system reduce the flow area of the turbine. The first-stage nozzle group is typically most affected by deposition of scale although scale may be present in other parts of the System. The most common deposits are of silica and calcium carbonate. This decreases the output capacity and efficiency of the turbine. This paper presents the results of simulations on the effect of scale deposition in the first-stage nozzle group on the steam pressure before and after the first stage, output capacity and efficiency of the turbine. By measuring the steam pressure before and after the first stage the change in the flow area can be estimated. A method of monitoring the percentage of nozzle plugging in real time is proposed. The method can be applied to any turbine that is susceptible to scale deposition. (C) 2002 CNR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Auton Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca, Morelos, Mexico. Inst Invest Elect Gerencia Turbomaquinaria, Temixco 62490, Morelos, Mexico. RP Kubiak, JA, Univ Auton Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001,Col Chamilpa,CP 62210, Cuernavaca, Morelos, Mexico. CR COTTON KC, 1993, EVALUATING IMPROVING CRAIG HRM, 1970, P I MECH ENG, V185, P407 KINDL FH, 1996, JOINT POWER GENERATI, V2, P471 KUBIAK JA, 1988, HEAT RECOVERY SYSTEM, V8, P529 KUBIAK JA, 1991, COMPUTERS ENG, V1, P631 NR 5 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD OCT PY 2002 VL 31 IS 5 BP 545 EP 562 PG 18 SC Energy & Fuels; Geosciences, Multidisciplinary GA 592KC UT ISI:000177936000002 ER PT J AU Martin, TJ Dulikravich, GS TI Analysis and multidisciplinary optimization of internal coolant networks in turbine blades SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID HEAT-TRANSFER; FLOW; TURBOMACHINERY; ALGORITHM AB The theoretical methodology, conceptual demonstration, and validation of a fully automated computer program for the inverse design and optimization of internal convectively cooled three-dimensional axial gas turbine blades is presented. A parametric computer model of the three-dimensional internal cooling network was developed, including the automatic generation of computational grids. A boundary element computer program was written to solve the steady-state, nonlinear heat conduction equation inside the internally cooled and thermal barrier coated turbine blade. A finite element algorithm was written to model an arbitrary network of internal coolant passages for the calculation of the internal pressure losses, How rates, effects of centrifugal pumping, heating of the coolant fluid, and heat transfer coefficients from the thermal model of the solid to the coolant fluid. The heat conduction and internal flow analyses were strongly and iteratively coupled to account for the heat balance between the blade and the coolant fluid. A system of evolutionary optimization algorithms was used to modify the internal cooling configuration and internal heat transfer enhancements (boundary-layer trip strips and pedestals) to achieve the objectives of increased cooling effectiveness and greater durability against oxidation, corrosion, and creep. The computer-automated design and optimization system was demonstrated on the second high-pressure turbine blade row of the Pratt and Whitney F100 engine. The internal cooling optimization on the product definition of this blade yielded a 5% increase in average cooling effectiveness, with only a marginal increase in coolant flow rate, in addition to having the same corrosion life and a doubling of the creep life. C1 Pratt & Whitney Engine Co, Turbine Discipline Engn & Optimizat Grp, E Hartford, CT 06108 USA. Univ Texas, Dept Mech & Aerosp Engn, Inverse Design & Optimizat Lab, Arlington, TX 76019 USA. RP Martin, TJ, Pratt & Whitney Engine Co, Turbine Discipline Engn & Optimizat Grp, 400 Main St,Mail Stop 165-16, E Hartford, CT 06108 USA. CR BREBBIA CA, 1978, BOUNDARY ELEMENT MET BRILLERT D, 1999, 99GT251 ASME CHIMA RV, 1987, J PROPUL POWER, V3, P397 CHIMA RV, 1995, 960248 AIAA CRAWFORD ME, 1976, CR2742 NASA DENNIS BH, 2001, J PROPUL POWER, V17, P1123 DIPPREY DF, 1963, INT J HEAT MASS TRAN, V6, P329 DULIKRAVICH GS, 1999, EUROGEN 99 EVOLUTION, P231 GIEL PW, 1998, J TURBOMACH, V120, P305 GRITSCH M, 1997, 97GT165 ASME HAN JC, 1988, INT J HEAT MASS TRAN, V31, P183 HAN JC, 1994, J TURBOMACH, V116, P149 HAN ZX, 2001, INT J TURBO JET ENG, V18, P47 HOLMAN JP, 1981, HEAT TRANSFER KAWAIKE K, 1992, P INT S HEAT TRANSF LAKSHMINARAYANA B, 1996, FLUID DYNAMICS HEAT, P597 LARSON FR, 1952, T ASME, V74, P765 MARTIN TJ, 1997, 13 INT S AIRBR ENG 1, V2, P1232 MARTIN TJ, 1999, 99GT146 ASME MARTIN TJ, 2001, SERIES ADV BOUNDARY, P137 MARTIN TJ, 2001, THESIS PENNSYLVANIA MENON MN, 1992, P 5 INT C CREEP MAT MOCHIZUKI S, 1994, J TURBOMACH, V116, P133 PRESS WH, 1986, NUMERICAL RECIPES FO SCHLICHTING H, 1979, BOUNDARY LAYER THEOR WEBB RL, 1998, PRINCIPLES ENHANCED, P229 WHITE FM, 1974, VISCOUS FLUID FLOW, P454 WHITE FM, 1988, HEAT MASS TRANSFER, P285 WHITE FM, 1994, FLUID MECH, P342 NR 29 TC 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 2002 VL 18 IS 4 BP 896 EP 906 PG 11 SC Engineering, Aerospace GA 575EQ UT ISI:000176934100025 ER PT J AU Kong, C Sugiyama, Y Soutis, C TI Structural design and experimental investigation of a medium scale composite wind turbine blade considering fatigue life SO SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS LA English DT Article DE composite wind turbine blade; structural design; load cases for wind turbine; fatigue life prediction; full scale static test AB The aim of this study was to make a structural design for development of a medium scale E-glass/epoxy composite wind turbine blade for a 750KW class horizontal axis wind turbine system. In this study, the various load cases specified by international specification IEC61400-1 and GL Regulations for the wind energy conversion system were considered, and a specific composite structure configuration which can effectively endure aerodynamic, centrifugal, hygro-thermal and mechanical loads and loads due to accumulation of ice was proposed. In order to evaluate the structure, a structural analysis for the composite wind turbine blade was performed using the finite element method (FEM). In the structural design, the acceptable blade structural configuration was determined through parametric studies, and the most dominant design parameters were confirmed. In the stress analysis using the FEM, it was confirmed that the blade structure was safe and stable in any of the various load cases. Moreover, the safety of the blade root joint with insert bolts, newly devised in this study, was checked against the design load and the fatigue. The fatigue life time over 20 years was estimated by using the well-known S-N linear damage equation, the load spectrum and Spera's empirical equations. With the results obtained from the structural design and analysis, the prototype composite blades were manufactured. The construction process and lay-up molding method developed in this study were employed to manufacture the prototype blades. Finally, a full-scale static structural test was performed with the simulated aerodynamic loads. From the experimental results, it was found that the designed blade had structural integrity. Furthermore, the measured results were in good agreement with the analytical results such as deflections, strains, the mass and the radial center of gravity. C1 Chosun Univ, Div Aerosp & Naval Architectural Engn, Kwangju 501759, South Korea. Univ Osaka Prefecture, Dept Aerosp Engn, Sakai, Osaka 591, Japan. Univ London Imperial Coll Sci Technol & Med, Dept Aeronaut, London, England. RP Kong, C, Chosun Univ, Div Aerosp & Naval Architectural Engn, Kwangju 501759, South Korea. CR 1985, IND MAGAZINE *EMRC, 1992, NISAII US MAN VERS 5 ACKERMANN T, 2000, RENEW SUST ENERG REV, V4, P315 BECHLY ME, 1997, COMPUT STRUCT, V63, P639 DELFT DRV, 1991, FULL SCALE FATIGUE T GOURIERES DLE, 1982, WIND POWER PLANTS TH INOMATA N, 1999, RENEW ENERG, V16, P912 KIM JS, 2000, RENEWABLE ENERGY DEV KONG C, 1999, J KSPE, V3, P40 KONG C, 2000, J KSPE, V4, P22 KONG C, 2000, J KSPE, V4, P29 KONG C, 2000, KSAS INT J, V1, P1 KONG C, 2000, P 3 AS PAC C AER TEC, P376 KONG C, 2000, STUDY STRUCTURAL AER KONG C, 2001, 13 INT C COMP MAT IC MANDELL JF, 1992, SAND927005 MAYER RM, 1996, DESIGN COMPOSITE STR, P195 MINER MA, 1945, J APPL MECH, V12, P159 PALMGREN A, 1924, Z VER DTSCH ING, V68, P339 SPERA DA, 1993, WINDPOWER, V93, P282 VEERS PS, 1993, WINDPOWER, V93, P342 ZWEBEN C, 1989, MECH BEHAV PROPERTIE, V1 NR 22 TC 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-181X J9 SCI ENG COMPOS MATER JI Sci. Eng. Compos. Mater. PY 2002 VL 10 IS 1 BP 1 EP 9 PG 9 SC Materials Science, Composites GA 572UZ UT ISI:000176794500001 ER PT J AU Daleo, JA Ellison, KA Boone, DH TI Metallurgical considerations for life assessment and the safe refurbishment and requalification of gas turbine blades SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Metallurgical analysis of rotating blades operating in advanced gas turbine engines is important in establishing actual operating conditions, degradation modes, remaining life, arid most importantly, the proper repair and rejuvenation techniques to be used in developing optimum component life strategies. The elevated firing temperatures used in the latest engine designs result not only in very high metal surface temperatures but also in very high temperature gradients anti concommitant thermal strains induced it? part by the complex and efficient cooling systems. This has changed the primary function of today's superalloy-coating systems from one of hot corrosion protection to moderating high temperature oxidation reactions. Furthermore, as a result of the high thermal strains induced by the cooling systems, long-terra metallurgical structural stability issues now revolve around optimizing both thermal mechanical fatigue (TMF) resistance and creep life. Thus the gradual change to directionally solidified (DS) arid single crystal (SC) alloys throughout the industry. The use of DS and SC alloys coated with state of the art TBC, platinum modified aluminide and MCrAlY coatings with or without subsequent aluminizing applied by vacuum plasma spray (VPS), high velocity oxygen fuel (HVOF), physical vapor deposition (PVD), air plasma spray (APS), and by chemical vapor deposition (CVD) methods along with the widespread use of internal aluminide coatings have made today's rotating components prohibitively expensive to replace after only one cycle of operation. It is therefore, or should now be a high priority for all cost conscious gas turbine users to help develop reliable repair and rejuvenation strategies and techniques to minimize their operating cost. Traditional metallurgical considerations required for life assessment and the reliable refurbishment and requalification of gas turbine blades are reviewed along with some new exciting techniques. Examples of component degradation modes are presented. Appropriate attention to metallurgical issues allows turbine users to more successfully and economically operate their turbines. C1 BWD Turbines Ltd, Ancaster, ON L9G 4V5, Canada. RP Daleo, JA, BWD Turbines Ltd, 1-601 Tradewind Dr, Ancaster, ON L9G 4V5, Canada. CR *ASM, 1983, ASM MET REF BOOK, P415 BEDDOES JC, 1980, METALLOGRAPHY, V13, P185 DALEO JA, 1996, FAIL 96 RISK EC SAF, P187 DALEO JA, 1997, 97GT186 ASME DALEO JA, 1998, ASME, V121, P375 DALEO JA, 1999, J ENG GAS TURB POWER, V121, P129 DANIELS A, 1995 ASNT QUAL TEST DANIELS A, 1996, THERM 18 INT C THERM ELLISON KA, 1998, P 6 LIEG C 3, P1523 LARSON FR, 1952, T ASME, V74, P765 LEE D, 1971, MET T, V2, P1245 MONKMAN FC, 1956, P ASTM, V56, P593 ODING IA, 1959, CREEP STRESS RELAXAT RAIRDEN JR, 1982, 30995, US ROBINSON EL, 1952, T ASME, V74, P777 SCHILKE PW, 1992, ADV MATER PROCESS, V4, P22 SODERBERG CR, 1936, T ASME, V58, P733 STIGLISH JJ, 1999, MAT SOLUTIONS 98, P138 TIEN JK, 1989, SUPERALLOYS SUPERCOM, P138 WELLS C, 1996, GE9620 STRUCT INT AS WOODFORD DA, 1992, SUPERALLOYS 92, P657 WOODFORD DA, 1993, MATER DESIGN, V14, P231 WOODFORD DA, 1999, P C HER WATT U, P293 WOODFORD DR, 1996, ANAL SERVICE RUN RUS NR 24 TC 9 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 2002 VL 124 IS 3 BP 571 EP 579 PG 9 SC Engineering, Mechanical GA 568CP UT ISI:000176525100018 ER PT J AU Kerr, C Ivey, P TI An overview of the measurement errors associated with gas turbine aeroengine pyrometer systems SO MEASUREMENT SCIENCE & TECHNOLOGY LA English DT Article DE temperature; pyrometry; measurement errors; gas turbine AB It is advantageous to operate the thermodynamic cycle of an aeroengine at as high a turbine entry temperature as practical for the current metallurgical limits Of the turbine blades, in order to achieve peak cycle efficiency and thus lower specific fuel consumption. However, achieving the highest possible turbine entry temperature requires accurate knowledge of the turbine blade temperatures for control purposes to prolong component life, as frequent excursions beyond the design limits of the blades can severely reduce their service life. The optical pyrometry technique represents the best method for providing these crucial temperature data needed for blade condition based monitoring. However, this method of non-contact temperature measurement is subject to a number of errors inherent to the gas turbine operating environment. In this paper we present the general operating principles and an overview of the measurement errors associated with optical pyrometry, together with a discussion of the techniques to prevent, limit and compensate for such errors resulting from the turbine environment. C1 Cranfield Univ, Sch Engn, Gas Turbine Instrumentat Grp, Dept Power Propuls & Aerosp Engn, Cranfield, Beds, England. RP Kerr, C, Cranfield Univ, Sch Engn, Gas Turbine Instrumentat Grp, Dept Power Propuls & Aerosp Engn, Cranfield, Beds, England. CR *BRIT STAND I, 1989, 1041 BS BRIT STAND 5 ALARURI SD, 1998, OPT ENG, V37, P683 ANDERSON RC, 1998, 20 AIAA ADV MEAS GRO ATKINSON WH, 1987, AIAA SAE ASME ASEE 2 ATKINSON WH, 1988, NASACR182111 ATKINSON WH, 1994, NASACR195283 BAYLEY FJ, 1972, HEAT TRANSFER BECKER WJ, 1989, AIAA ASME SAE ASEE 2 BENNETHUM WH, 1988, NASACR180900 BEYNON TGR, 1981, ASME GAS TRUB C PROD BEYNON TGR, 1982, HIGH TEMPERATURE TEC, P85 DELUCIA M, 1994, T AM SOC MECH ENG, V116, P172 DELUCIA M, 1999, 99GT311 ASME DOUGLAS J, 1980, P JOINT FLUIDS ENG G FISHER EA, 1993, 5203632, US GRAY WA, 1976, HEAT TRANSFER FLAMES HAYDEN T, 1988, AIAA ASME SAE ASEE 2 INCROPERA FP, 1985, INTRO HEAT TRANSFER KERR CI, 2001, 4L ASME INT GAS TURB KIRBY PJ, 1986, INT GAS TURB C EXH D LEFEBVRE AH, 1984, INT J HEAT MASS TRAN, V27, P1493 LEFEBVRE AH, 1999, GAS TURBINE COMBUSTI LUDWIG CB, 1973, HDB INFRARED RAD COM MCNICHOLAS K, 1988, PAESKMN4520 ROLLS RO MCNICHOLAS K, 1994, EPGP3078 ROLLS ROYC MOSSEY PW, 1969, 690431 SAE NUTTER GD, 1985, STP895 ASTM SUAREZ E, 1988, AIAA ASME SAE ASEE 2 SUAREZ E, 1993, AIAA SAE ASME ASEE 2 SUAREZGONZALEZ E, 1987, 4657386, USEZ SUAREZGONZALEZ E, 1987, 4708474, US SUAREZGONZALEZ E, 1987, 5125739, US SUAREZGONZALEZ E, 1993, 5265036, USLEZ TOTHILL MH, 1989, THESIS CRANFIELD I T NR 34 TC 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD JUN PY 2002 VL 13 IS 6 BP 873 EP 881 PG 9 SC Engineering, Multidisciplinary; Instruments & Instrumentation GA 566XE UT ISI:000176452900008 ER PT J AU Nalla, RK Boyce, BL Campbell, JP Peters, JO Ritchie, RO TI Influence of microstructure on high-cycle fatigue of Ti-6Al-4V: Bimodal vs. lamellar structures SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID CRACK-GROWTH THRESHOLDS; STRESS-INTENSITY FACTOR; FOREIGN-OBJECT DAMAGE; SMALL SURFACE CRACKS; MIXED-MODE; TITANIUM-ALLOY; WIDMANSTATTEN TI-6AL-4V; SENSITIVE FATIGUE; ROOM-TEMPERATURE; ASPECT RATIO AB The high-cycle fatigue (HCF) of titanium alloy turbine engine components remains a principal cause of failures in military aircraft engines. A recent initiative sponsored by the United States Air Force has focused on the major drivers for such failures in Ti-6Al-4V, a commonly used turbine blade alloy, specifically for fan and compressor blades. However, as most of this research has been directed toward a single processing/heat-treated condition, the bimodal (solution-treated and overaged (STOA)) microstructure, there have been few studies to examine the role of microstructure. Accordingly, the present work examines how the overall resistance to high-cycle fatigue in Ti-6Al-4V compares between the bimodal microstructure and a coarser lamellar (beta-annealed) microstructure. Several aspects of the HCF problem are examined. These include the question of fatigue thresholds for through-thickness large and short cracks; microstructurally small, semi-elliptical surface cracks; and cracks subjected to pure tensile (mode I) and mixed-mode (mode I + II) loading over a range of load ratios (ratio of minimum to maximum load) from 0.1 to 0.98, together with the role of prior damage due to sub-ballistic impacts (foreign-object damage (FOD)). Although differences are not large, it appears that the coarse lamellar microstructure has improved smooth-bar stress-life (S-N) properties in the HCF regime and superior resistance to fatigue-crack propagation (in pure mode I loading) in the presence of cracks that are large compared to the scale of the microstructure; however, this increased resistance to crack growth compared to the bimodal structure is eliminated at extremely high load ratios. Similarly, under mixed-mode loading, the lamellar microstructure is generally superior. In contrast, in the presence of microstructurally small cracks, there is little difference in the HCF properties of the two microstructures. Similarly, resistance to HCF failure following FOD is comparable in the two microstructures, although a higher proportion of FOD-induced microcracks are formed in the lamellar structure following high-velocity impact damage. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Gen Motors, Met Fabricat Div, Troy, MI 48084 USA. Tech Univ Hamburg, D-21073 Hamburg, Germany. RP Nalla, RK, Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. CR *US AIR FORC SCI A, 1992, REP ADH COMM AIR FOR ADACHI S, 1985, P 5 INT C TIT SCI TE, P2139 BACHE MR, 1997, J MATER SCI, V32, P3435 BACHE MR, 1997, MAT SCI ENG A-STRUCT, V234, P918 BOYCE BL, 2001, ENG FRACT MECH, V68, P129 BOYCE BL, 2001, MECH MATER, V33, P441 BOYCE BL, 2001, THESIS U CALIFORNIA BROWN CW, 1983, FATIGUE ENG MATER, V6, P67 CAMPBELL JP, 2000, ENG FRACT MECH, V67, P209 CAMPBELL JP, 2000, ENG FRACT MECH, V67, P229 CAMPBELL JP, 2001, METALL MATER TRANS A, V32, P497 CHANG JCI, 1996, AIR FORCE OFFICE SCI CHESNUTT JC, 1951, TITANIUM 80 SCI TECH, V2, P1875 CHESNUTT JC, 1978, AFMLTR7668 COWLES BA, 1996, INT J FRACTURE, V80, P147 DAVIDSON DL, 1980, METALL TRANS A, V11, P837 DAWSON DB, 1974, MET T, V5, P723 DOKER H, 1982, FATIGUE THRESHOLDS, V1, P45 ELHADDAD MH, 1979, ENG FRACT MECH, V11, P573 EVANS WJ, 1994, INT J FATIGUE, V16, P443 EYLON D, 1998, SUMMARY AVAILABLE IN GAO H, 1982, FATIGUE ENG MATER ST, V5, P1 GREGORY JK, 1994, HDB FATIGUE CRACK PR, P281 HALLIDAY MD, 1981, J TEST EVAL, V9, P195 HE MY, 2000, ENG FRACT MECH, V65, P1 HE MY, 2000, J APPL MECH-T ASME, V67, P207 HERMAN WA, 1988, FATIGUE FRACT ENG M, V11, P303 HINES JA, 1999, FATIGUE BEHAV TITANI, P15 IRVING PE, 1974, MATER SCI E, V14, P229 KITAGAWA H, 1976, P 2 INT C MECH BEH M, P627 KRUZIC JJ, 1999, ACTA MATER, V47, P801 LENETS YN, 2000, INT J FATIGUE, V22, P521 LUCAS JJ, 1973, TITANIUM SCI TECHNOL, V3, P2081 LUKAS P, 1987, ENG FRACT MECH, V26, P471 LUTJERING G, 1993, TITANIUM 92 SCI TECH, P1635 LUTJERING G, 1998, MAT SCI ENG A-STRUCT, V243, P32 MARCI G, 1996, FATIGUE 96, V1, P493 MAYER HR, 1998, UNPUB MURAKAMI Y, 1999, FATIGUE FRACT ENG M, V22, P581 NAYEBHASHEMI H, 1982, METALLURGICAL T A, V13, P2197 NEWMAN JC, 1981, ENG FRACT MECH, V15, P185 NICHOLAS T, 1980, EXP MECH, V20, P357 OGAWA T, 1993, FATIGUE FRACT ENG M, V16, P973 PETERS JO, 2000, ENG FRACT MECH, V67, P193 PETERS JO, 2000, METALL MATER TRANS A, V31, P1571 PETERS JO, 2001, IN PRESS INT J FATIG PETERS JO, 2001, P INT C FAT VER HIGH, P129 PETERS M, 1984, METALL TRANS A, V15, P1597 PUSTEJOVSKY MA, 1979, ENG FRACT MECH, V11, P17 PUSTEJOVSKY MA, 1979, ENG FRACT MECH, V11, P9 RAVICHANDRAN KS, 1990, SCRIPTA METALL MATER, V24, P1559 RAVICHANDRAN KS, 1991, ACTA METALL MATER, V39, P401 RAVICHANDRAN KS, 1997, METALL MATER TRANS A, V28, P149 RAVICHANDRAN KS, 1997, METALL MATER TRANS A, V28, P157 RITCHIE RO, 1986, MATER SCI ENG, V84, P11 RITCHIE RO, 1986, SMALL FATIGUE CRACKS, P167 RITCHIE RO, 1996, P ASME AEROSPACE DIV, V52, P321 RITCHIE RO, 1999, FATIGUE FRACT ENG M, V22, P621 SHELDON JW, 1999, INT J FATIGUE, V21, P733 SINHA V, 2000, MAT SCI ENG A-STRUCT, V287, P30 SMITH MC, 1988, ASTM STP, V924, P260 SURESH S, 1984, INT MET REV, V29, P445 TAYLOR D, 1985, COMPENDIUM FATIGUE T THOMAS JP, 1998, SCRIPTA MATER, V39, P1647 THOMPSON AW, 1999, FATIGUE BEHAV TITANI, P23 TONG J, 1994, FATIGUE FRACT ENG M, V17, P829 TSCHEGG EK, 1983, ACTA METALL, V31, P1323 WAGNER L, 1984, P 2 INT C SHOT PEEN, P194 WANHILL RJH, 1974, CORROSION, V30, P28 WATERHOUSE RB, 1994, EUROPEAN STRUCTURAL, V18 WILLIAMS JC, 1981, TITANIUM 80 SCI TECH, V1, P671 YODER GR, 1977, METALL TRANS A, V8, P1737 YODER GR, 1979, ENG FRACT MECH, V11, P805 YODER GR, 1983, ENG FRACT MECH, V17, P185 NR 74 TC 10 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 2002 VL 33 IS 3 SI Sp. Iss. SI BP 899 EP 918 PG 20 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 564TB UT ISI:000176328700024 ER PT J AU Kerr, CI Ivey, PC TI A review of purge air designs for aeroengine-based optical pyrometers SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB With the advent of "power by the hour" type agreements within the civil aeroengine market, the application of engine system monitoring system data has reached the level of strategic use for inforined decision making in not only the aftennarket but increasingly in the contract negotiation stage, One of the key cost drivers in these dollar-per-hour contracts for the OEMs to analyze is the life and maintenance requirements of the turbine blades leading ultimately to blade life management. Such life management of key components is of critical importance to ensure that the economic and technical risks to both service provider and customer are minimized. The optical pyrometer, through providing a direct, temperature measurement of the turbine blades, is a primary input for providing a more realistic assessment of the component's operating history associated with the use of life usage/remaining algorithms. However, the greatest concern with the in-service use of pyrometry is the issue of fouling since the pyrometer's lens is exposed to the turbine environment. The level of optical contamination is usually minimized by introducing purge air bled from the compressor; down the sight tube to prevent both the build-up of contaminants on the exposed system optics and particles in the gas stream from coming in contact with the lens. This paper provides a review of purge air designs and the key methodologies for engine designers to be acquainted with when seeking to integrate the use of optical pyrometry systems in new engine concepts. C1 Cranfield Univ, Sch Mech Engn, Cranfield MK43 0AL, Beds, England. RP Kerr, CI, Cranfield Univ, Sch Mech Engn, Cranfield MK43 0AL, Beds, England. CR ATKINSON WH, 1978, IEEE ERA EL 78 C REC BARBER R, 1969, NAT AIR TRANSP M NEW BERENBLUT BJ, 1982, BR J NONDESTR TEST, V24, P268 BISWAS P, 1988, J AEROSOL SCI, V19, P113 CRAFT DW, 4738528, US DAVINSON I, 1984, 00862 EIR ROLLS ROYC DELAMORA JF, 1990, J AEROSOL SCI, V21, P889 DELUCIA M, 1994, ASME, V116, P172 HARLEY JF, 1981, 4306835, US HAYDEN T, 1988, AIAA ASME SAE ASEE 2 HOLMQVIST G, 1980, 4240691, US KAST HB, 1995, 5421652, US KIRBY PJ, 1986, PROP EN PAN 67 S PHI MACKAY CG, 1990, 4934137, US MYHRE DC, 1988, 4786188, US MYHRE DC, 1992, 5146244, US OBRIEN RJ, 1989, 4836689, US PENNEY CM, 1988, 4784491, US POINTER J, 1985, 2158576, GB RIDLEY IH, 1997, 5599105, US SELLERS RR, 1989, AIAA ASME SAE ASEE 2 SUAREZGONZALEZ E, 1987, 4657386, USEZ NR 22 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD APR PY 2002 VL 124 IS 2 BP 227 EP 234 PG 8 SC Engineering, Mechanical GA 547PQ UT ISI:000175341300011 ER PT J AU Dinc, S Demiroglu, M Turnquist, N Mortzheim, J Goetze, G Maupin, J Hopkins, J Wolfe, C Florin, M TI Fundamental design issues of brush seals for industrial applications SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB Advanced seals have been applied to numerous turbine machines over the last decade to improve the performance and output. Industrial experiences have shown that significant benefits can be attained if the seals are designed and applied properly. On the other hand, penalties can be expected if brush seals are not designed correctly. In recent Years, attempts have been made to apple, brush seals to more challenging locations with high speed (>400 m/s), high temperature (>650degreesC), and discontinuous contact surfaces, such as blade tips in a turbine, Various failure modes of a brush seal can be activated under these conditions. It becomes crucial to understand the physical behavior of a brush seal under the operating conditions, and to be capable of quantifying seal life and performance as functions of both operating parameters and seat design parameters. Design criteria are required for different failure modes such as stress, fatigue, creep, wear, oxidation etc. This paper illustrates some of the most important brush seal design criteria and the trade-off of different design approaches. C1 GE Res & Dev Ctr, Schenectady, NY 12309 USA. GE Power Generat, Greenville, SC 29602 USA. GE Power Generat, Schenectady, NY 12345 USA. RP Dinc, S, GE Res & Dev Ctr, Schenectady, NY 12309 USA. CR AKSIT MF, 1999, 992827 AIAA CHEN LH, 1999, 99GT281 AIAA CHUPP RE, 1997, 33 AIAA ASME SAE ASE DINE S, 1998, 983175 AIAA SODITUS SM, 1998, 983284 AIAA TURNQUIST A, 1999, 992682 AIAA NR 6 TC 8 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD APR PY 2002 VL 124 IS 2 BP 293 EP 300 PG 8 SC Engineering, Mechanical GA 547PQ UT ISI:000175341300019 ER PT J AU Arakere, NK Swanson, G TI Effect of crystal orientation on fatigue failure of single crystal nickel base turbine blade superalloys SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID STRESS AB High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493, PWA 1484, RENE' N-5 and CMSX-4. These alloys play an important role in commercial, military and space propulsion systems. Single crystal materials have highly, orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. The failure modes of single crystal turbine blades are complicated to predict due to the material orthotropy and variations in crystal orientations. Fatigue life estimation of single crystal turbine blades represents an important aspect of durability assessment. It is therefore of practical interest to develop effective fatigue failure criteria for single crystal nickel alloys and to investigate the effects of variation of primary and secondary crystal orientation on fatigue life. A fatigue failure criterion based on the maximum shear stress amplitude [Deltatau(max)] on the 24 octahedral and 6 cube slip systems, is presented for single crystal nickel superalloys (FCC crystal). This criterion reduces the scatter in uniaxial LCF test data considerably for PWA 1493 at 1200degreesF in air. Additionally, single crystal turbine blades used in the alternate advanced high-pressure fuel turbopump (AHPFTP/AT) are modeled using a large-scale three-dimensional finite element model This finite element model is capable of accounting for material orthotrophy and variation in primary and secondary crystal orientation. Effects of variation in crystal orientation on blade stress response are studied based on 297 finite element model runs. Fatigue lives at critical points in the blade are computed using finite element stress results and the failure criterion developed. Stress analysis results in the blade attachment region are also presented. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to significantly increase a component's resistance to fatigue crack growth without adding additional weight or cost. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NASA, George C Marshall Space Flight Ctr, Strength Anal Grp ED33, Huntsville, AL 35812 USA. RP Arakere, NK, Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. CR *PRATT WHITN, 1996, FR245811 P W BANANTIAE JA, 1985, ASTM S LOW CYCL FAT COWLES BA, 1996, INT J FRACTURE, V80, P147 DELUCA D, 1995, FATIGUE SINGLE CRYST DELUCA DP, 1989, HYDROGEN EFFECTS MAT FATEMI A, 1988, FATIGUE FRACT ENG M, V11, P149 KANDIL FA, 1982, BIAXIAL LOW CYCLE FA, P203 LEKHNITSKII SG, 1963, THEORY ELASTICITY AN, P1 MILLIGAN WW, 1985, DEFORMATION MODELING MOROSO J, 1999, THESIS U FLORIDA GAI SAYYAH T, 1999, ALTERNATE TURBOPUMP SMITH KN, 1970, J MATER, V5, P767 SOCIE DF, 1985, 2 INT S MULT FAT SHE STOUFFER DC, 1996, INELASTIC DEFORMATIO TELESMAN J, 1989, ENG FRACT MECH, V34, P1183 NR 15 TC 7 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2002 VL 124 IS 1 BP 161 EP 176 PG 16 SC Engineering, Mechanical GA 547ML UT ISI:000175336100022 ER PT J AU Cairo, RR Sargent, KA TI A scientific approach to the process development bonded attachments for high-speed rotor application SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB The quest for increased work per stage of compression to reduce overall gas turbine engine system cost has placed extreme demands on the high-pressure turbine (HPT) system. As an example, the HPT is required to operate at unprecedented levels of AN(2) (the product of turbine annulus area and mechanical speed squared) to enable compressor performance goals to be met. The typical approach of mechanically attaching blades via firtree or dovetail configured mechanical attachments, limits rotor speed because of the life limiting broach slots (stress concentrators) in the disk rim. Exacerbating this problem is the fact that the disk lugs, which react the blade loading, impose a dead load. Higher disk speed results in higher blade loading requiring a deeper or wider lug to support the blade. This in turn results in a wider disk bore to support the deeper, dead load lug region. The dilemma is that higher speed results in larger stress concentrations at the rim and a wider disk bore to support the added parasitic, rim load. The answer to this dilemma lies in creating an integrally bladed rotor (IBR) in which the blades are integral with the disk. Since typically, for an HPT the blades are single crystal and the disk equiaxed nickel alloys, the IBR design suggested precludes absolute machining as the fabrication approach. A solution lies in metallurgically bonding the blades to the disk rim. Bonded airfoil attachments have the potential to increase AN(2) and component life by 9-10 percent by eliminating broach induced stress concentrations as noted. Moreover, bonded attachments can reduce external rim loading by upward of 15 percent with a corresponding reduction in disk weight. The key to the solution is a controlled, economical process to concurrently join a full complement of HPT blades in a repeatable manner. This paper discusses how a scientific approach and creative design practice can lead to such a process. Three alternative tooling concepts, and one universal toot that allows independent use of two of these concepts, were developed. Tool stresses and deflections, tool load paths, and bond pressure profiles were all quantified through ANSYS finite element analyses and closed-form analytical solutions. Prior experience has shown that joint strength is sensitive to the bond pressure level. Therefore, the tool materials and geometry were iterated upon until the pressure applied to the blade bond plane was as uniform as possible. Since absolute uniformity is elusive when deformable bodies are part of the bond load train, accurately determining the maximum and minimum bond plane pressure is absolutely essential for subsequent joint characterization and design allowable determination. This allows localized working stresses in the designed attachment to be compared to specific, bond pressure driven, allowable strengths rather than cut average strength. This paper will show how applying a scientific approach to the development of a critical technology process can reduce both the cost and risk of process development. C1 Pratt & Whitney Aircraft, W Palm Beach, FL 33410 USA. USAF, Res Lab, AFRL, PRTC, Wright Patterson AFB, OH 45433 USA. RP Cairo, RR, GE Power Syst, Gas Turbine Technol Ctr, 300 Garlington Rd, Greenville, SC 29602 USA. CR CAIRO RR, 1909, 88GT505 ASME CAIRO RR, 1999, AFRLPRWPTR19992050 NR 2 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2002 VL 124 IS 1 BP 190 EP 195 PG 6 SC Engineering, Mechanical GA 547ML UT ISI:000175336100025 ER PT J AU MacLachlan, DW Knowles, DM TI The effect of material behaviour on the analysis of single crystal turbine blades: Part II - Component analysis SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE creep; fatigue; finite element simulation; micromechanism; single-crystal superalloy; turbine blade component ID CREEP; SUPERALLOYS; PREDICTION AB This paper describes the analysis of a turbine blade component using a slip system model developed for modern single-crystal superalloys. Structural elasto-viscoplastic calculations are carried out for the component. The emphasis throughout is on the effect of micromechanisms of deformation, accounted for in the material model, on the predicted overall behaviour of the component. With the recent proliferation in detailed material models that are available, it is prudent to take a step back and investigate the implications of such models for component analysis and design. This effect is manifested through the determination of a stabilised and redistributed stress state throughout the component. While some components are creep-limited in design, many are fatigue-limited and it is stabilised stresses which control the cyclic life of these components. The accuracy of the material model, incorporating various micromechanisms as a function of stress and temperature, can significantly effect these stabilised stresses. The effect of the crystallographic orientation on blade behaviour is illustrated and the implications of shakedown simulations for fatigue lifing of turbine blades are discussed. C1 Univ Cambridge, Dept Mat Sci, Rolls Royce UTC, Cambridge CB2 3QZ, England. RP MacLachlan, DW, Rolls Royce PLC, PCF-33,POB 31, Derby DE24 8BJ, England. CR CHEN LJ, 2000, FATIGUE FRACT ENG M, V23, P509 DUNNE FPE, 1992, P ROY SOC LOND A MAT, V437, P567 MACLACHLAN DW, IN PRESS COMP MAT SC MACLACHLAN DW, 2001, FATIGUE FRACT ENG M, V24, P503 MACLACHLAN DW, 2001, INT J PLASTICITY, V17, P441 MACLACHLAN DW, 2001, MAT SCI ENG A-STRUCT, V302, P275 MACLACHLAN DW, 2002, FATIGUE FRACT ENG M, V25, P385 NR 7 TC 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD APR PY 2002 VL 25 IS 4 BP 399 EP 409 PG 11 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 546KT UT ISI:000175273800006 ER PT J AU See, DW Dulaney, JL Clauer, AH Tenaglia, RD TI The air force manufacturing technology laser peening initiative SO SURFACE ENGINEERING LA English DT Article ID FATIGUE AB Laser peening has been demonstrated to be a unique and valuable method to increase the resistance of aircraft gas turbine engine compressor and fan blades to foreign object damage (FOD) and improve high cycle fatigue (HCF) life. Laser peening is also known as the LaserPeen* process (LPP) or laser shock processing (LSP). LaserPeen processing's high value as a surface enhancement process to mitigate high cycle fatigue failures is driving efforts to expand its application from gas turbine engines to aircraft structures, land vehicles, weapon systems, and for general industrial use. One of the major impediments to the broad acceptance and use of the LaserPeen process has been high processing costs with relatively low throughput. Great strides are being made to significantly decrease laser peening costs and increase throughput, thanks to three important Air Force ManTech (manufacturing technology) programmes being conducted at LSP Technologies, Inc. (LSPT). Several key issues are being addressed to meet Man Tech goals to lower costs and increase throughput, which include the development of production quality laser peening services and equipment and the expansion of the end user base for this technology. Additionally, a fourth ManTech programme is being conducted by Universal Technology, Corporation (UTC) in conjunction with LSPT Pratt & Whitney, and Howmet. The objective of this programme is to demonstrate that expensive wrought turbine engine blades can be replaced with low cost cast blades, which have been LaserPeen processed. (C) 2002 IoM Communications Ltd. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. LSP Technol Inc, Dublin, OH 43016 USA. RP See, DW, USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. CR CLAUER AH, P 5 NAT TURB ENG HIG CLAUER AH, 1992, DURABILITY METAL AIR, P350 CLAUER AH, 1996, SURFACE PERFORMANCE, P217 CLAUER AH, 2000, DUR SURF S INT MECH, P121 PEYRE P, 1998, J MATER SCI, V33, P1421 PEYRE P, 2000, MAT SCI ENG A-STRUCT, V280, P290 RUSCHAU JJ, 1999, J ENG MATER-T ASME, V121, P321 SEE DW, 2001, P 6 NAT TURB ENG HIG THOMPSON SD, 1997, SURFACE PERFORMANCE, P239 NR 9 TC 6 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 0267-0844 J9 SURF ENG JI Surf. Eng. PY 2002 VL 18 IS 1 BP 32 EP 36 PG 5 SC Materials Science, Coatings & Films GA 536TQ UT ISI:000174718300003 ER PT J AU Ito, A Sugiyama, K Shinohara, N Sugita, Y Sakurai, S Kameda, J TI In-service degradation of metallurgical and mechanical properties of aluminized coatings and substrates in gas turbine blades SO MATERIALS TRANSACTIONS LA English DT Article DE gas turbine; blade; coating; nickel-base superalloy; degradation; small punch test; mechanical property ID SMALL-PUNCH; COCRALY COATINGS AB In-service degradation of metallurgical and mechanical properties of aluminized CoCrAlY coatings and Ni-base superalloy substrates in advanced gas turbine blades has been studied. The aluminized coatings of the unexposed and in-service exposed blades consisted of four layers with different microstructure and chemical composition. In-service environmental attack led to the deposition of Fe oxides on the top aluminized coating and formation of a thin-layered Al2O3. While in-service, Ni diffused extensively from the substrate into the near-surface coating region. The interdiffusion of Co/Ni resulted in the formation of Al/Ni rich precipitates in all the coating regions, except a near-surface coating region indicating Cr rich precipitates. A number of Cr rich precipitates were found in the substrate near the interdiffusion zone. The near-interface coating region and substrate softened at room and elevated temperatures. The ductility and low cycle fatigue life of the internal coating region at room temperature was not degraded. However, the ductility of the internal and near-interface coating regions and substrate at elevated temperatures was substantially degraded. In-service mechanical degradation of the aluminized CoCrAlY coatings is discussed in light of the metallurgical evolution. C1 Chubu Elect Power Co Inc, Elect Power Res & Dev Ctr, Nagoya, Aichi 4598522, Japan. Hitachi Ltd, Mech Engn Res Lab, Hitachi, Ibaraki 3178511, Japan. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Ito, A, Chubu Elect Power Co Inc, Elect Power Res & Dev Ctr, Nagoya, Aichi 4598522, Japan. CR BAIK JM, 1983, SCRIPTA METALL, V17, P1443 BRIGGS D, 1983, PRACTICAL SURFACE AN, CH5 CHANG WH, 1972, SUPERALLOYS PROCESSI, P41 CHEUVU NS, 1998, 98GT511 ASME DALEO JA, 1997, P INT GAS TURBINE AE ELLISON KA, 1998, MAT ADV POWER ENG, V5, P1523 ITO A, IN PRESS J SOC MAT S ITOH Y, 1995, J SOC MATER SCI JPN, V44, P1361 KAMEDA J, 1992, J MATER SCI, V27, P983 KAMEDA J, 1997, MAT SCI ENG A-STRUCT, V229, P42 KAMEDA J, 1997, MAT SCI ENG A-STRUCT, V234, P489 KAMEDA J, 1998, 98GT527 ASME KAMEDA J, 1999, J THERM SPRAY TECHN, V8, P440 MAO XY, 1987, J NUCL MATER, V150, P42 MASSALSKI TB, 1990, BINARY ALLOY PHASE D, V2, P1179 MASSALSKI TB, 1990, BINARY ALLOY PHASE D, V2, P136 RAINDEN JR, 1982, 30995, RE SUGITA Y, 1995, P MATERIAL AGEING CO, P307 SUGITA Y, 1997, 97GT532 ASME VILLARS P, 1995, HDB TERNARY ALLOY PH, V3, P3002 WLODEK ST, 1999, P S LONG TERM STAB H, P3 WOODFORD DA, 1990, P EPRI ASM LIF ASS R, P97 NR 22 TC 0 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI, 980, JAPAN SN 1345-9678 J9 MATER TRANS JI Mater. Trans. PD JAN PY 2002 VL 43 IS 1 BP 11 EP 18 PG 8 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 530KY UT ISI:000174357900003 ER PT J AU Sajjadi, SA Nategh, S Guthrie, RIL TI Study of microstructure and mechanical properties of high performance Ni-base superalloy GTD-111 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE GTD-superalloy; gamma-precipitates; tensile properties; creep resistance ID FRACTURE BEHAVIOR; CREEP; DEPENDENCE; ALLOY; CAST AB The Ni-base superalloy GTD-111 is widely used in manufacturing of the first stage blades of high power land-based gas turbines. In spite of its important role in increasing the performance of gas turbines. due to high temperature capability, there are little data on the microstructure, deformation mechanisms and mechanical properties of the alloy. The aim of present paper is to determine in details these properties. Microstructural characteristics of the alloy were assessed by means of optical, scanning and transmission electron microscopy. The tensile behaviour of GTD-111 has been studied in the temperature range 25-900 degreesC. The results showed abnormal variations in tensile properties with increasing temperature. TEM observations confirmed that these behaviours were affected by the gamma' properties and a change in the mechanism of deformation of GTD-111 at high temperatures. From creep test results, Larson-Miller and Monkman-Grant plots were produced which are used for life prediction. It was also observed that several creep deformation mechanisms operate at various combinations of temperature and stress. (C) 2002 Published by Elsevier Science B.V. C1 Sharif Univ Technol, Fac Mat Sci & Technol, Tehran 8639, Iran. McGill Univ, Dept Min & Met Engn, Montreal, PQ H3A 2B2, Canada. RP Sajjadi, SA, Sharif Univ Technol, Fac Mat Sci & Technol, Azadi Ave,POB 11365, Tehran 8639, Iran. CR *ASTM, 1998, E139 ASTM *ASTM, 1998, E21 ASTM *ASTM, 1998, E8 ASTM BETTERIDE W, 1974, NIMONIC ALLOYS OTHER, P45 BETTGE D, 1995, Z METALLKD, V86, P190 BIEBER CG, 1970, 2 INT C STRENGTH MET, P1031 BROOKS CR, 1982, HEAT TREATMENT STRUC, P139 CASTILLO R, 1987, J ENG GAS TURB POWER, V109, P99 DALEO JA, 1998, J ENG GAS TURB POWER, P120 DAVIES PW, 1960, SPECIAL REPORT, P34 DENNISON JP, 1962, J I MET, V91, P343 DENNISON JP, 1978, MATER SCI ENG, V33, P35 FELLERKNIEPMEIER M, 1989, METALL TRANS A, V20, P1233 GABB TP, 1987, SUPERALLOYS, V2, P291 GAUDENZI GP, 1996, P C EL TEMP COAT SCI, P301 HENDERSON PJ, 1983, ACTA METALL, V31, P1203 JIANTING G, 1983, METALL T A, V14, P2329 KOUL AK, 1984, MATER SCI ENG, V66, P213 LARSON FR, 1952, T ASME, V74, P765 MONKMAN FC, 1956, P ASTM, V56, P593 POPE DP, 1984, INT MET REV, V29, P136 SAJJADI SA, 2001, MAT SCI ENG A-STRUCT, V307, P158 SAJJADI SA, 2001, UNPUB CAN METALL MAY SCHILKE PW, 1992, ADV MATER PROCESS, V4, P22 SMIALEK JL, 1987, SUPERALLOYS, V2, P291 STEVENS RA, 1978, J MATER SCI, V13, P367 STEVENS RA, 1981, ACTA METALL, V29, P867 WILLIAMS KR, 1977, MATER SCI ENG, V28, P289 NR 28 TC 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD FEB 28 PY 2002 VL 325 IS 1-2 BP 484 EP 489 PG 6 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 525PR UT ISI:000174080600058 ER PT J AU Arakere, NK Orozco, E TI Analysis of Low Cycle Fatigue properties of single crystal nickel-base turbine blade superalloys SO HIGH TEMPERATURE MATERIALS AND PROCESSES LA English DT Article DE Low Cycle Fatigue; single crystal superalloy; turbine blade; PWA1480; SC 7-14-6; high temperature; high-pressure hydrogen AB Hot section components in high performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys such as PWA1480, PWA1484, CMSX-4 and Rene N-4 as these materials provide superior creep, stress rupture, melt resistance and thermomechanical fatigue capabilities over their polycrystalline counterparts. These alloys play an important role in commercial, military and space propulsion systems. A detailed analysis of the experimentally determined Low Cycle Fatigue (LCF) properties for PWA 1493/1480 and SC 7-14-6 single crystal materials as a function of specimen crystallographic orientation is presented, over a wide temperature range of 75F to 1800 F. The data presented includes an extensive compilation of LCF data for single crystal nickel-base material at high temperature and in high-pressure hydrogen and air. Fatigue failure parameters are investigated for LCF data of single crystal material based on the shear and normal stress and strain amplitudes on the 30 possible slip systems for FCC single crystals. The max shear stress amplitude on the slip planes reduces the scatter in the LCF data and is found to be a good fatigue damage parameter, especially at elevated temperatures. Fatigue life equations are developed for various temperature ranges and environmental conditions based on power-law curve fits of the failure parameter with LCF test data. C1 Univ Florida, Dept Engn Mech, Gainesville, FL 32611 USA. RP Arakere, NK, Univ Florida, Dept Engn Mech, Gainesville, FL 32611 USA. CR *PRATT WHITN, 1996, FR245811 PW ARAKERE NK, IN PRESS ASME ARAKERE NK, 2000, ASME IGTI C MAY MUN BANANTINE JA, 1985, ASTM S LOW CYCL FAT DALAL RP, 1984, SUPERALLOYS 1984, P185 DELUCA D, 1995, FR23800 DEP NAV OFF DELUCA DP, 1989, HYDROGEN EFFECTS MAT FATEMI A, 1988, FATIGUE FRACT ENG M, V11, P149 GELL M, 1986, PROCESSING PROPERTIE, P41 JACKSON JJ, 1977, METALL T A, V8, P1615 KANDIL FA, 1982, BIAXIAL LOW CYCLE FA, P203 KEAR BH, 1967, T AIME, V239, P1209 LEKHNITSKII SG, 1963, THEORY ELASTICITY AN, P1 MCLEAN M, 1983, DIRECTIONALLY SOLIDI, P151 MOROSO J, 1999, THESIS U FLORIDA GAI PETERS BJ, INVESTIGATION ADV PR SHAH DM, 1984, SUPERALLOYS 1984, P105 SMITH KN, 1970, J MATER, V5, P767 SOCIE DF, 1985, 2 INT S MULT FAT SHE STOUFFER DC, 1996, INELASTIC DEFORMATIO NR 20 TC 1 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6455 J9 HIGH TEMP MATER PROCESS JI High Temp. Mater. Process. PD DEC PY 2001 VL 20 IS 5-6 BP 403 EP 419 PG 17 SC Materials Science, Multidisciplinary GA 526UX UT ISI:000174149000011 ER PT J AU Gallardo, JM Rodriguez, JA Herrera, EJ TI Failure of gas turbine blades SO WEAR LA English DT Article DE gas-turbine failure; wear; thermal expansion; coating failure AB The first-stage blades of a gas turbine had suffered a severe deterioration after around 10 500 h service. The expected service life was 40 000 h. Failure analysis (visual observations, studies by optical microscopy, scanning electron microscopy (SEM), SEM back-scattered electron (SEM-BSE), EDX, X-ray diffraction (XRD) and dimensional metrology) has been carried out. Blades, manufactured in the nickel superalloy CMSX-4, lost the protective coatings from their tips due to wear. Unprotected surfaces suffered high-temperature hot corrosion (Type-I corrosion). It is concluded that failure was mainly caused by an uneven clearance (out-of-line) between rotor and lining. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Sevilla, Grp Met & Ingn Mat, ES Ingn, Seville 41092, Spain. RP Gallardo, JM, Univ Sevilla, Grp Met & Ingn Mat, ES Ingn, Camino Descubrimientos S-N, Seville 41092, Spain. CR *ALL, 1987, ALL HDB LOSS PREV, P385 *ASM INT, 1990, ASM MET HDB, V1, P995 *ASM, 1987, ASM MET HDB, V13, P1000 ELSNER W, 1998, ALLIANZ REP, V2, P97 ERICKSON GL, 1997, ADV MATER PROCESS, V3, P27 GOWARD GW, 1988, T ASME, V110, P150 GOWARD GW, 1998, SURF COAT TECH, V108, P73 LEHNERT G, 1972, ELECTRODEPOSITION SU, V1, P189 RESTALL JE, 1986, MAT SCI TECHNOL, V12, P2625 SMITH WF, 1981, STRUCTURE PROPERTIES, P485 STOIBER J, 1998, ALLIANZ REP, V4, P236 STRINGER J, 1998, SURF COAT TECH, V108, P1 WARNES BM, 1997, SURF COAT TECH, V94, P1 NR 13 TC 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD FEB PY 2002 VL 252 IS 3-4 BP 264 EP 268 PG 5 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 524HM UT ISI:000174007200010 ER PT J AU Roux, JM Mahe, P Sauthier, B Duboue, JM TI Aerothermal predictions with transition models for high-pressure turbine blades SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY LA English DT Article DE numerical simulation; heat transfer; high-pressure turbine blade; transition models; turbulence models ID TURBULENCE AB Turbine aerothermal analysis is a key issue of the entire engine design as higher performance and longer component life must always be reached. For this purpose, a substantial effort is dedicated to aerothermal methods at Snecma-Moteur. This paper deals with the problem of heat transfer prediction on uncooled turbine blades. The main parameter investigated is the transition process, but consideration is also given to the turbulence model, effect of free stream turbulence on laminar boundary layer and mesh refinement. All the models are implemented in a three-dimensional Navier-Stokes code. Quasi-three-dimensional computations are used to evaluate all models, and then fully three-dimensional computations are performed. Aerothermal predictions are compared with static pressure and heat transfer measurements from the IACA and TATEF Brite-EuRam programmes carried out in the test facilities of DERA, Pyestock and the von Karman Institute. C1 Snecma Moteur, Turbine Aero & Cooling Dept, F-77550 Moissy Cramayel, France. RP Roux, JM, Snecma Moteur, Turbine Aero & Cooling Dept, F-77550 Moissy Cramayel, France. CR ABUGHANNAM BJ, 1980, J MECH ENG SCI, V22, P213 BOYLE RJ, 1998, 98GT367 ASME DRELA M, 1995, MISES IMPLEMENTATION EDWARDS JR, 2000, 20000133 AIAA HILDITCH MA, 1996, AGARD C P, P571 LIAMIS N, 1995, 952335 AIAA MAYLE RE, 1991, J TURBOMACH, V113, P509 RAMESH ON, 1999, 3 EUR C TURB SCHMIDT RC, 1991, J TURBOMACH, V113, P18 SIEVERDING CH, 1998, LS199802 VKI SMITH MC, 1966, PHYS FLUIDS, V9, P2337 STEELANT J, 1999, 3 EUR C TURB WILCOX DC, 1994, AM I AERONAUT ASTRON, V32, P237 NR 13 TC 2 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0957-6509 J9 PROC INST MECH ENG A-J POWER JI Proc. Inst. Mech. Eng. Part A-J. Power Energy PY 2001 VL 215 IS A6 BP 735 EP 742 PG 8 SC Engineering, Mechanical GA 522ER UT ISI:000173883200009 ER PT J AU Sayyah, MT Schonberg, WP TI New failure criterion for space shuttle main engine turbine blades SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB The orientation of a single-crystal material is known to affect the strength and life of structural component parts. Results are presented of an investigation of the effects of secondary axis orientation angles on the failure of the first-stage of the space shuttle main engine alternate turbopump development of the high-pressure fuel turbopump. First, the correlation of different failure models with low-cycle fatigue data for nickel-base single-crystal test specimens was analyzed. Then the models with the highest correlation coefficients were used to study the actual single-crystal blade structure. Based on the results obtained, a new failure model was proposed. A detailed finite element model for the first-stage blade was used to calculate the stresses and strains at all blade nodes for different material orientations. Results of the analysis showed that the critical value of the failure model could vary by up to a factor of 3 by changing the primary and secondary material orientations. A comparison between analytical results and engine test results showed good correlation and also demonstrated the dependence of cracking location on crystal orientation. C1 Sverdrup Technol Inc, Huntsville, AL 35814 USA. Univ Missouri, Dept Civil Engn, Rolla, MO 65409 USA. RP Sayyah, MT, Sverdrup Technol Inc, POB 11541, Huntsville, AL 35814 USA. CR *ANSYS INC, 1996, ANSYS STRUCT PROGR V ABDULAZIZ A, 1993, COMPUT STRUCT, V46, P249 AZIZ A, 1993, TM106125 NASA BANNANTINE J, 1990, FUNDAMENTALS METAL F BEER F, 1981, MECH MAT, CH10 BOWEN K, 1986, 861477 AIAA BROWN MW, 1973, P I MECH ENG, V187, P745 CHANDLER W, 1985, CP2372 NASA, P110 DRESHFIELD R, 1987, 871976 AIAA DUHL DN, 1989, SUPERALLOYS SUPERCOM, P149 FATEMI A, 1988, J ENG MATER-T ASME, V110, P380 FINDLEY WN, 1959, ASME J ENG IND, V81, P301 FRITZEMEIER L, 1989, CR182244 NASA KALLURI S, 1997, SAE T 1, V100, P273 KANDIL FA, 1982, METALS SOC, V280, P203 LEE H, 1991, ANSYS C P SWANS SYST, V2 SAYYAH MT, 1999, THESIS U ALABAMA HUN SOCIE D, 1985, P 2 INT S MULT FAT STOUFFER D, 1996, INELASTIC DEFORMATIO, CH8 NR 19 TC 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKET JI J. Spacecr. Rockets PD JAN-FEB PY 2002 VL 39 IS 1 BP 140 EP 145 PG 6 SC Engineering, Aerospace GA 523AE UT ISI:000173928500019 ER PT J AU Shepherd, DP Wisbey, A Harrison, GF Ward, TJ Vermeulen, B TI Cyclic operation of aero gas turbines - materials and component life implications SO MATERIALS AT HIGH TEMPERATURES LA English DT Article DE aero gas turbines AB Historically, the issues connected with the lifing of power generation gas turbine components have been very different from those associated with aero engines. Specifically, component lives in the power generation application have been dictated by creep and high cycle fatigue, whereas low cycle fatigue has been the driver for aero engines. However, developments in the design and usage of gas turbines within the respective industries have resulted in this distinction becoming increasingly blurred. This paper highlights recent advances in the materials technology, stress analysis and lifing of aero engine components, which are potentially relevant to industrial gas turbines. In particular, the development of complex constitutive equations for modelling plasticity and anisotropic creep are discussed, with particular reference to the behaviour of single crystal turbine blades. Moreover, developments in the methodologies used to estimate safe service lives for the components are considered. Specifically, a new lifing procedure, capable of accurately predicting component lives from plain specimen data alone, is discussed. C1 QinetiQ Ltd, Struct & Mat Ctr, Engine Mat & Lifting, Farnborough GU14 0LX, Hants, England. RP Shepherd, DP, QinetiQ Ltd, Struct & Mat Ctr, Engine Mat & Lifting, Farnborough GU14 0LX, Hants, England. CR 1990, JOINT AVIATION REQUI HARRISON GF, COMPASS 99 HARRISON GF, P 5 EUR PROP FOR PIS HOMEWOOD T, 1998, P C MOD MICR EV CREE LEMAITRE J, 1990, MECH SOLIDS MAT LORD PC, 2000, 70325 DNS MROZ Z, 1969, ACTA MECH, V7, P199 SHEPHERD DP, 2000, DERAMSSMSTR2CR003081 WARD TJW, 2000, DERAMSSMSMA1CR003609 WINSTONE MR, 2000, P 5 INT C PARS TURB, P779 NR 10 TC 4 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81,, NORTHWOOD HA6 3DN, MIDDX, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2001 VL 18 IS 4 BP 231 EP 239 PG 9 SC Materials Science, Multidisciplinary GA 515CX UT ISI:000173478800005 ER PT J AU Rott, M Igenbergs, E Baur, H Glitz, G TI Domestic object damage investigations on turbine blade material SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article DE domestic object damage; turbine blades; particle impacts; TiAl alloys AB Domestic Object Damage (DOD) is a problem, especially for compressor and turbine sections of jet engines, To investigate the influence on the performance and service life of the impacted components, well defined DOD impacts in the laboratory have been performed with consecutive metallurgical investigations and fatigue testing. The paper describes the efforts to upgrade the existing flat coil accelerator at the Fachgebiet Raumfahrttechnik (Irt) to the needs of the DOD tests and documents the experiment set up. Particles were shot on ideal flat specimens of Titanium Aluminides (gamma-TiAl based alloys) under realistic service conditions simulating stress and/or temperature of the target. First experimental results are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Tech Univ Munich, Fachgebiet Raumfahrttechn, D-85748 Garching, Germany. Daimler Chrysler AG, Forsch & Technol, D-89081 Ulm, Germany. RP Rott, M, Tech Univ Munich, Fachgebiet Raumfahrttechn, Boltzmannstr 15, D-85748 Garching, Germany. CR AUSTIN CM, 1995, GAMMA TITANIUM ALUMI, P21 BAUR H, 1999, COMMUNICATION CLEMENS H, 1997, HIGH TEMPERATURE ORD, V7, P29 IGENBERGS E, 1986, IEEE T MAGNETICS MAG, V6, P1536 ROTT M, 1993, IEEE T MAGN, V29, P597 NR 5 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 2001 VL 26 IS 1-10 BP 651 EP 662 PG 12 SC Engineering, Mechanical; Mechanics GA 510ZN UT ISI:000173237600059 ER PT J AU Matikas, TE TI Specimen design for fatigue testing at very high frequencies SO JOURNAL OF SOUND AND VIBRATION LA English DT Article AB Components in rotational machinery such as turbine blades used in military aircraft engines are subjected to low-amplitude, high-frequency loads in the kHz range. Under high cycle fatigue (HCF), the initiation state of a crack consumes most of the life of the component. Vibratory stresses may therefore result in unexpected failures of the material. Hence, there is a need for HCF studies to address HCF-related failures of turbine engines and to develop a life prediction methodology. Ultrasonic fatigue provides accelerated HCF testing enabling the simulation of realistic loading conditions for testing materials used in structural components subjected to vibratory stresses. Specimen design is critical for optimum ultrasonic fatigue testing. The objective of this study is therefore to develop analytical modelling necessary for the design of test coupons to be fatigue tested at ultrasonic frequencies. (C) 2001 Academic Press. C1 Greek Atom Energy Commiss, Athens, Greece. RP Matikas, TE, Greek Atom Energy Commiss, POB 60092,15310 Agia Paraskevi Attikis, Athens, Greece. CR 1999, FATIGUE FRACTURE ENG, V22 DROSSIS J, 1991, THESIS U TORONTO EISNER E, 1963, 216 HM STAT OFF EISNER E, 1964, J ACOUST SOC AM, V36, P309 HOFFELNER W, 1982, FATIGUE HIGH TEMPERA, P645 MASON WP, 1950, PIEZOELECTRIC CRYSTA, P161 MASON WP, 1951, J ACOUST SOC AM, V23, P209 MATIKAS TE, 2001, UNPUB FATIGUE FRACTU NEPPIRAS EA, 1959, P ASTM, V59, P691 SHOUP TE, 1984, APPL NUMERICAL METHO, P116 NR 10 TC 0 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD NOV 1 PY 2001 VL 247 IS 4 BP 673 EP 681 PG 9 SC Acoustics; Engineering, Mechanical; Mechanics GA 503LK UT ISI:000172799800006 ER PT J AU Itoh, Y Saitoh, M Takaki, K Fujiyama, K TI Effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE equiaxed IN738LC; fatigue life; MCrAlY coating; push-pull loading; rotational bending; single-crystal CMSX-2; superalloy; unidirectional solidified CM247LC ID LOW-CYCLE FATIGUE; MECHANICAL-PROPERTIES AB This study concerns MCrAlY coatings (M is Ni, Co or both) sprayed by a vacuum plasma spraying process for protection against high-temperature corrosion and oxidation of gas turbine components, such as turbine blades and duct segments. The effect of high-temperature protective coatings on fatigue lives of nickel-based superalloys were investigated at high temperature under push-pull loading and rotary bending and then compared with uncoated superalloys, such as equiaxed IN738LC, unidirectional solidified CM247LC and single-crystal CMSX-2. The high-cycle fatigue lives of MCrAlY-coated superalloys at high temperature under push-pull loading showed an inferior performance when compared with the uncoated superalloys. This was because the crack initiation site was different. The high-cycle fatigue cracks of nickel-based superalloys initiated at casting cavities which were exposed on the specimen surface, whereas the high-cycle fatigue cracks of MCrAlY-coated specimens initiated at interface defects, such as small pores and grid residue, between the MCrAlY coating and the substrate and grew into the MCrAlY coating, and then into the substrate. Similarly, the rotary bending fatigue properties of MCrAlY-coated superalloys at high temperature showed an inferior performance when compared with the uncoated superalloys. This is because of a high stress due to the higher Young's modulus of the MCrAlY coating (in comparison with the substrate) being induced at the MCrAlY coating surface. The crack initiation site was on the specimen surface in both cases of the nickel-based superalloys and the MCrAlY-coated superalloys, respectively. As a result, it was considered that, for rotary bending tests, the fatigue life reduction was due to the high stress that originated from the difference of elastic constants between the MCrAlY coating and the superalloy. Consequently, in fatigue life design it is necessary to take account of the stress levels in a coating layer. C1 Toshiba Co Ltd, Power & Ind Syst R&D Ctr, Tsurumi Ku, Yokohama, Kanagawa 2300045, Japan. RP Itoh, Y, Toshiba Co Ltd, Power & Ind Syst R&D Ctr, Tsurumi Ku, 2-4 Suehiro Cho, Yokohama, Kanagawa 2300045, Japan. CR BETTRIDGE DF, 1986, MATER SCI TECH SER, V2, P232 GAYDA J, 1986, INT J FATIGUE, V8, P217 IBRAHIM A, 1998, J MATER SCI, V33, P3095 ITOH Y, 1999, J ENG GAS TURB POWER, V121, P476 ITOH Y, 1999, J MATER SCI, V34, P3957 MEVREL R, 1989, MAT SCI ENG A-STRU 1, V120, P13 OKAZAKI M, 1990, METALL TRANS A, V21, P2201 SCHNEIDER K, 1983, THIN SOLID FILMS, V107, P395 VEYS JM, 1987, MATER SCI ENG, V88, P253 WOOD MI, 1989, MAT SCI ENG A-STRUCT, V121, P633 NR 10 TC 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD DEC PY 2001 VL 24 IS 12 BP 843 EP 854 PG 12 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 503NU UT ISI:000172805200007 ER PT S AU Tamarin, YA Zherzdev, SV TI Technological aspects of forming TBC-EB ceramic layers SO HIGH TEMPERATURE CORROSION AND PROTECTION OF MATERIALS 5, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article DE interaction 'ceramics-bond coat'; life of ceramic layers; reduction; thermal barrier coating; turbine blade; zirconia AB Adhesive strength at the interface of the top coat of yttria stabilised zirconia (YSZ) and the bond coat depends on a number of technological factors. Some procedures are used to form YSZ layers with long service lives. They are based on "the concept of reduction", that is the use of partial zirconia reduction due to its dissociation under vacuum. YSZ dissociation facilitates the formation of free metal cations in it. In this case high adhesive strength results from diffusion processes which occur at the interface of the ceramic layer and the metallic bond coat. They make possible the formation of an interlayer. During YSZ condensation bond coating elements diffuse into the ceramic layer to the depth of up to 10 mum. The ceramic layers formed by the processes based on "the concept of reduction" feature high service lives at 1100 degreesC. C1 Sci Consulting Ctr, AVIA, VIAM, RU-111555 Moscow, Russia. RP Tamarin, YA, Sci Consulting Ctr, AVIA, VIAM, Molostovich St 11-6-15, RU-111555 Moscow, Russia. CR DEMCHISHIN AV, 1980, THESIS KIEV JASLIER Y, 1997, 85 M STRUCT MAT PAN, P8 KULIKOV IS, 1986, THERMODYNAMICS OXIDE MARTIROSYAN AM, 1987, PROBLEMS SPECIAL MET, V2, P47 MOVCHAN BA, 1983, HEAT RESISTANT COATI MOVCHAN BA, 1996, IOM NOV, P40 STRANGMAN TE, 1982, 4321311, US STRANGMAN TE, 1985, THIN SOLID FILMS, V127, P93 TAMARIN YA, 1988, 1642783, RU TAMARIN YA, 1989, 1633754, RU TAMARIN YA, 1990, WIRTSCHAFT TECHNIK, V2, P47 TAMARIN YA, 1991, MECH CREEP BRITTLE M, V2, P308 ULION NE, 1983, 4414249, US NR 13 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2001 VL 369-3 PN Part 1&2 BP 587 EP 593 PG 7 SC Materials Science, Multidisciplinary GA BT27T UT ISI:000172513200067 ER PT J AU Monies, F Rubio, W Redonnet, JM Lagarrigue, P TI Comparative study of interference caused by different position settings of a conical milling cutter on a ruled surface SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE LA English DT Article DE five-axis numerical control machining; conical mill; ruled surfaces AB This article covers the side milling of ruled surfaces using a conical milling cutter. This problem, encountered in real-life industrial situations, concerns parts such as turbine blades that entail problems of accessibility. To deal with this, industrialists use conical milling cutters that can mill the base of the blades while the larger main body of the milling cutter can be applied to the end of the blade. In the present article, five types of positioning on ruled surfaces are introduced, including two developed within the Toulouse Mechanical Engineering Laboratory. These position settings, studied for cylindrical milling cutters, were able to be adapted to the conical milling cutter. A comparative study was then made of these five position settings from the point of view of interference between the milling cutter and the theoretical surface. Working from two ruled surfaces (one hyperbolic paraboloid and one ruled surface of any nature), different tests were: performed, with variation in the milling cutter geometry (end of milling cutter radius and half-angle at the apex). The results obtained made it possible to validate improved positioning, and this led to an industrial contract with the SAPEX-PROFOR Company. A final example based on a turbine blade is given. C1 Lab Genie Mecan Toulouse, UFR PCA, F-31062 Toulouse, France. RP Rubio, W, Lab Genie Mecan Toulouse, UFR PCA, Bat 3PN,118 Route Narbonne, F-31062 Toulouse, France. CR ELBER G, 1997, J MANUF SCI E-T ASME, V119, P383 FAUX ID, 1985, COMPUTATIONAL GEOMET LEE YS, 1998, COMPUT AIDED DESIGN, V30, P957 LIU XW, 1995, COMPUT AIDED DESIGN, V27, P887 MONIES F, 2000, P I MECH ENG B-J ENG, V214, P625 PETERNELL M, 1999, COMPUT AIDED DESIGN, V31, P17 QIULIN D, 1987, SURFACE ENG GEOMETRY REDONNET JM, 1998, 2 SCI INT C INT DES REDONNET JM, 1998, INT J ADV MANUF TECH, V14, P459 REHSTEINER F, 1993, ANN CIRP, V42, P457 RUBIO W, 1998, INT J ADV MANUF TECH, V14, P13 STUTE G, 1979, ANN CIRP, V28, P267 NR 12 TC 5 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0954-4054 J9 PROC INST MECH ENG B-J ENG MA JI Proc. Inst. Mech. Eng. Part B-J. Eng. Manuf. PY 2001 VL 215 IS 9 BP 1305 EP 1317 PG 13 SC Engineering, Manufacturing; Engineering, Mechanical GA 496VC UT ISI:000172416900013 ER PT J AU Mino, K Imamura, R Koiwai, H Fukuoka, C TI Residual life prediction of turbine blades of aeroderivative gas turbines SO ADVANCED ENGINEERING MATERIALS LA English DT Article C1 Ishikawajima Harima Heavy Ind Co Ltd, Koto Ku, Tokyo 1358732, Japan. RP Mino, K, Ishikawajima Harima Heavy Ind Co Ltd, Koto Ku, 3-1-15 Toyosu, Tokyo 1358732, Japan. CR AURRECOECHEA JM, 1990, ASME90GT23 GOLDHOFF RM, 1972, T ASME, V94, P1 MINO K, 2000, J JPN I MET, V64, P50 VISWANATHAN R, 1989, DAMAGE MECH LIEFE AS NR 4 TC 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1438-1656 J9 ADV ENG MATER JI Adv. Eng. Mater. PD NOV PY 2001 VL 3 IS 11 BP 922 EP 924 PG 3 SC Materials Science, Multidisciplinary GA 497TV UT ISI:000172472300020 ER PT J AU Griffin, DA Zuteck, MD TI Scaling of composite wind turbine blades for rotors of 80 to 120 meter diameter SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) Program, a scaling study was performed oil composite wind turbine blades. The study's objectives were to assess the scaling of current commercial blade materials and manufacturing technologies for rotors of 80 to 120 meters in diameter, to develop scaling curves of estimated weight and cost for rotor blades in that size range, and to identify practical limitations to the scaling of current conventional blade manufacturing and materials. Aerodynamic and structural calculations were performed for a matrix of baseline blade design parameters, and the results were used as a basis for constructing a computational scaling model. The scaling model was then used to calculate structural properties for a wide range of aerodynamic designs and rotor sizes. Blade designs were evaluated oil the basis of power performance, weight, static strength in flapwise bending, fatigue life in edgewise bending, and tip deflection under design loads. Calculated results were compared with weight data for current commercial blades, and limitations were identified for scaling lip the baseline blade configurations. A series of parametric analyses was performed to quantify the weight reductions possible by modifying the baseline design and to identify the practical limits of those modifications. The model results provide insight into the competing design considerations involved in scaling up current commercial blade designs. C1 Global Energy Concepts LLC, Kirkland, WA 98033 USA. MDZ Consulting, Kemah, TX 77565 USA. RP Griffin, DA, Global Energy Concepts LLC, 5729 Lakeview Dr NE,Suite 100, Kirkland, WA 98033 USA. CR *GLOB EN CONC LLC, 2000, DAT BLAD SPEC MEG SC *INT EL COMM, 1999, 614001 IEC EPPLER R, 1980, TM80210 NASA GERMANISCHER L, 1999, RULES REGULATIONS 4 GIGUERE P, 2000, P AIAA ASME WIND EN, P266 GRIFFIN DA, 2001, NRELSR50029492 HARRISON R, 1994, W3400170REP ETSU U S MALCOLM DJ, 2001, P WINDP 2001 AM WIND MANDELL JF, 1997, SAND973002 SAND NAT SELIG MS, 1994, NRELCP50016336 SOMMER J, 2000, COMMUNICATION 0512 TANGLER JL, 1995, P WINDP 95 WASH DC A, P117 NR 12 TC 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2001 VL 123 IS 4 BP 310 EP 318 PG 9 SC Energy & Fuels; Engineering, Mechanical GA 494WM UT ISI:000172308900012 ER PT J AU Moriarty, PJ Eggers, AJ Chaney, K Holley, WE TI Scale and lag effects on control of aerodynamic power and loads on a HAWT rotor SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The effects of rotor scale and control system lag were examined for a variable-speed wind turbine. The scale study was performed on a teetered rotor with radii ranging between 22.5m and 33.75m. A 50% increase in radius more than doubled the rated power and annual energy capture. Using blade pitch to actively control fluctuating flatwise moments allowed for significant reductions in blade mass for a fixed fatigue life. A blade operated in closed-loop mode with a 33.75m radius weighed less than an open-loop blade with a 22.5m radius while maintaining the same fatigue life of 5x10(9) rotations. Actuator lag reduced the effectiveness of the control system. However 50% reductions in blade mass were possible even when implementing a relatively slow actuator with a 1 sec. time constant. Other practical limits on blade mass may include fatigue from start/stop cycles, non-uniform turbulence, tower wake effects, and wind shear The more aggressive control systems were found to have high control accelerations near 60 de g/s(2), which may be excessive for realistic actuators. Two time lags were introduced into the control system when mean wind speed was estimated in a rapidly changing wind environment. The first lag was the length of time needed to determine mean wind speed, and therefore the mean control settings. The second was the frequency at which these mean control settings were changed. Preliminary results indicate that quickly changing the mean settings (every 10 seconds) and using a moderate length mean averaging time (60 seconds) resulted in the longest fatigue life. It was discovered that large power fluctuations occurred during open loop operation which could cause sizeable damage to a realistic turbine generator These fluctuations are reduced by one half or more when aerodynamic loads are actively controlled. C1 RANN Inc, Palo Alto, CA 94303 USA. RP Moriarty, PJ, RANN Inc, 744 San Antonio Rd,Suite 26, Palo Alto, CA 94303 USA. CR DOWNING SD, 1982, INT J FATIGUE, V4, P31 EGGERS AJ, 1995, P 16 ASME WIND EN S, P31 EGGERS AJ, 1996, J SOL ENERG-T ASME, V118, P239 EGGERS AJ, 1999, 1999 ASME WIND EN S, P104 HANSEN AC, 1997, USERS GUIDE WIND TUR MANDELL JF, 1993, 1993 DOE NREL WIND E ROCK SM, 2000, 2000 ASME WIND EN S SCHLUTER LL, 1991, SAND902259 SAND NAT NR 8 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 2001 VL 123 IS 4 BP 339 EP 345 PG 7 SC Energy & Fuels; Engineering, Mechanical GA 494WM UT ISI:000172308900016 ER PT J AU Sabbagh, HA Sabbagh, EH Murphy, RK Nyenhuis, J TI Assessing thermal barrier coatings by eddy current inversion SO MATERIALS EVALUATION LA English DT Article DE eddy current nondestructive testing; electromagnetic inverse problems; thermal barrier coatings; thin film metrology; advanced gas turbines AB Nondestructive testing (NDT) of high temperature coatings is one of the important factors in achieving a high level of structural integrity in advanced gas turbines. In this paper, we demonstrate that sophisticated eddy current techniques can be utilized to measure the thickness and remaining life of high temperature coatings. Some research has been conducted to apply such techniques to the preservice case, for which the coating has one nicely defined layer and nothing of consequence has diffused into the base metal that would create additional layers of anomalous material. We discuss the much more difficult inservice case, in which the time temperature exposure of the combustion turbine blade has created a four layered system, in addition to the base metal. C1 Victor Technol LLC, Bloomington, IN 47407 USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Sabbagh, HA, Victor Technol LLC, POB 7706, Bloomington, IN 47407 USA. CR *EPRI, 2000, MICR MEAS DAT DESTR *EPRI, 2000, PERF DEM PROT ROUND HARRISON DJ, 1996, J NONDESTRUCT EVAL, V15, P21 OGAWA K, 2000, MAT EVALUATION MAR, P476 STRANGMAN TE, 1985, THIN SOLID FILMS, V127, P93 NR 5 TC 2 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD NOV PY 2001 VL 59 IS 11 BP 1307 EP 1312 PG 6 SC Materials Science, Characterization & Testing GA 491LR UT ISI:000172110400005 ER PT J AU Rao, JS Pathak, A Chawla, A TI Blade life: A comparison by cumulative damage theories SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID TRANSIENT AB A turbine blade is modeled as a rotating pretwisted beam and subjected to aerodynamic excitation from the flow path interference. The resonant stresses are determined using a modal analysis. With the help of steady steam bending and centrifugal stresses and the dynamic stresses, life estimates are made using the linear and nonlinear cumulative damage theories and a comparison of the results is presented. Based on these results, recommendations are made on the usefulness of different theories for practical application. C1 Indian Inst Technol, Dept Mech Engn, New Delhi 110016, India. RP Rao, JS, Indian Inst Technol, Dept Mech Engn, New Delhi 110016, India. CR BAGCI C, 1981, MECH MACH THEORY, V16, P339 BARSOM JM, 1987, FRACTURE FATIGUE CON BENEDICT B, 1997, CONT ED COURS ASME O CORTEN HT, 1956, P INT C FAT MET I ME, P235 GATTS RR, 1961, T ASME, V83, P529 HAIBACH E, 1989, BEITRIEBSFESTIGKEIT HENRY DL, 1955, T ASME, V77, P913 LEVIN A, 1953, MOVING BLADES DISKS MANSON SS, 1967, ASTM STP, V415, P384 MARCO SM, 1954, T ASME, V76, P627 MARIN J, 1962, MECH BEHAV MAT MINER MA, 1945, ASME, V67, A159 PALMGREN A, 1924, Z VER DTSCH ING, V68, P339 RAO JS, 1986, SHOCK VIBRATION B 2, V56, P109 RAO JS, 1991, TURBOMACHINE BLADE V RAO JS, 1992, ADV THEORY VIBRATION RAO JS, 1994, TURBOMACHINE UNSTEAD RAO JS, 1996, BLADE DYNAMICS LIFE RAO JS, 1996, J ENG GAS TURB POWER, V118, P424 RAO JS, 1998, DYNAMICS PLATES RAO MS, 1987, INT J PANCREATOL, V2, P1 SHIGLEY JE, 1983, MECH ENG DESIGN SINHA A, 1984, J ENG GAS TURB POWER, V106, P65 VYAS NS, 1994, J ENG GAS TURB POWER, V116, P198 WOHLER A, 1860, Z BAUWESEN NR 25 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2001 VL 123 IS 4 BP 886 EP 892 PG 7 SC Engineering, Mechanical GA 488KP UT ISI:000171934600023 ER PT J AU Lorenzo, CF Ray, A Holmes, MS TI Nonlinear control of a reusable rocket engine for life extension SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID DAMAGE-MITIGATING CONTROL; SYSTEMS AB The conceptual development and a design methodology are presented for life-extending control where the objective is to achieve high performance and structural durability of complex dynamic systems. A life-extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel (H-2) and oxidizer (O-2) turbine blades while satisfying the dynamic performance requirements of the combustion chamber pressure and O-2/H-2 mixture ratio. The design procedure makes use of a combination of linear and nonlinear techniques and also allows adaptation of the life-extending controller module to augment a conventional performance controller of the rocket engine. The nonlinear part of the controller is designed by optimizing selected parameters in a prescribed dynamic structure of damage compensation. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Penn State Univ, University Pk, PA 16802 USA. RP Lorenzo, CF, NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. CR BALAS GJ, 1993, MU ANAL SYNTHESIS TO BAMIEH BA, 1992, IEEE T AUTOMAT CONTR, V37, P418 DAI XW, 1996, J DYN SYST-T ASME, V118, P401 GILL PE, 1981, PRACTICAL OPTIMIZATI, P7 GILL PE, 1986, USERS GUIDE NPSOL VE HOLMES MS, 1998, J DYN SYST-T ASME, V120, P249 KALLAPPA P, 1997, AUTOMATICA, V33, P1101 LORENZO CF, 1991, IEEE CONTROL SYSTEMS, V12, P42 RAY A, 1994, J PROPUL POWER, V10, P225 RAY A, 1995, 4640 NASA CR LEW RES SCHITTKOWSKI K, 1985, COMPUTATIONAL MATH P, P383 VIDYASAGAR M, 1992, NONLINEAR SYSTEMS AN, P219 ZHANG H, 1999, J DYN SYST-T ASME, V121, P377 ZHOU K, 1996, ROBUST OPTIMAL CONTR, P449 NR 14 TC 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2001 VL 17 IS 5 BP 998 EP 1004 PG 7 SC Engineering, Aerospace GA 472VM UT ISI:000171005700007 ER PT J AU Chaboche, JL Gallerneau, F TI An overview of the damage approach of durability modelling at elevated temperature SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE creep; damage mechanics; fatigue; life prediction; oxidation ID LIFE PREDICTION; FATIGUE DAMAGE; CREEP-FATIGUE; RUPTURE; STRESS; STEEL AB Lifetime prediction techniques for components working at elevated temperature are revisited. Two damage approaches in which time effects at high temperature are introduced in different ways are discussed in greater detail. First, a creep-fatigue damage model considers the interaction of the two processes during the whole life before macrocrack initiation; and second, a creep-fatigue-oxidation model separates the fatigue life into two periods: during initiation the environment-assisted processes interact with fatigue, although bulk creep damage only interacts during the micropropagation period. The second model is illustrated by its application to a coated single-crystal superalloy used in aerojet turbine blades. Its capabilities are illustrated in a number of isothermal and thermomechanical fatigue tests. Anisotropy effects are also briefly discussed and a special test, introducing cyclic thermal gradients through the wall thickness of a tubular component, demonstrates the predictive capabilities for actual engine conditions. C1 Off Natl Etud & Rech Aerosp, DMSE, Chatillon, France. RP Chaboche, JL, Off Natl Etud & Rech Aerosp, DMSE, Chatillon, France. CR BROWN MW, 1973, P I MECH ENG, V187, P745 CAILLETAUD G, 1982, P C ASME PVP ORL FL CAILLETAUD G, 1984, NUCL ENG DES, V83, P267 CAILLETAUD G, 2000, J PHYS IV, V10, P181 CHABOCHE JL, 1974, REV FRANCAISE MECANI, V50, P71 CHABOCHE JL, 1977, ANN VITBTP S, V351, P117 CHABOCHE JL, 1977, S FRANC MEC CRAC, P137 CHABOCHE JL, 1978, AGARD C CHAR LOW CYC CHABOCHE JL, 1987, P C MECAMAT DOURD, P53 CHABOCHE JL, 1988, FATIGUE FRACT ENG M, V11, P1 CHABOCHE JL, 1996, RT1041765RY ONERA CHABOCHE JL, 1997, P 5 INT C BIAX MULT, P237 CHATAIGNER E, 1995, JOURNEES PRINTEMPS F COFFIN LF, 1954, T ASME, V76, P931 GAILERNEAU F, 1995, THESIS SCH MINES PAR GALLERNEAU F, 1999, INT J DAMAGE MECH, V8, P405 GALLERNEAU FD, 1996, P 6 INT FAT C FATIGU, P861 HALES R, 1980, FATIGUE FRACT ENG M, V3, P339 HALFORD GR, 1976, ASTM STP, V612, P239 HALFORD GR, 1980, J AIRCRAFT, V17, P598 HALFORD GR, 1983, 83023 NASA HAYHURST DR, 1972, J MECH PHYS SOLIDS, V20, P381 HUA CT, 1984, FATIGUE ENG MATER, V7, P165 KACHANOV LM, 1958, IZV AKAD NAUK USS TN, V8, P26 LAUTRIDOU JC, 1995, INT WORKSH FAT THERM, P110 LEMAITRE J, 1974, IUTAM S MECH VISC ME, P37 LEMAITRE J, 1978, J MEC APPL, V2, P317 LESNE PM, 1987, RECH AEROSPATIALE, P33 MANSON SS, 1965, T ASME, V87, P25 MANSON SS, 1966, INT J FRACT MECH, V2, P327 MANSON SS, 1981, INT J FRACTURE, V17, P169 MARCO SM, 1954, T ASME, V76, P627 MERIC L, 1991, J ENG MATER-T ASME, V113, P162 MILLER KJ, 1977, J STRAIN ANAL, V12, P57 MILLER KJ, 1981, FATIGUE ENG MATER ST, V4, P263 MILLER KJ, 2000, BEHAV SHORT FATIGUE NOUAILHAS D, 1991, HIGH TEMPERATURE CON, P151 NOUAILHAS D, 1995, EUR J MECH A-SOLID, V14, P137 NOUAILHAS D, 1997, 27283 ONEAR RTS RY D NOUAILHAS D, 1997, RT1051765RY ONERA OSTERGREN WJ, 1976, J TEST EVAL, V4, P327 PLUMTREE A, 1978, P ASME PRESS VESS PI RABOTNOV YN, 1969, CREEP PROBLEMS STRUC SAVALLE S, 1982, MICROPROPAGATION DAM, P395 SINES G, 1959, METAL FATIGUE, V20, P145 SOCIE DF, 1983, P ASME C LIF PRED AL, P96 SPERA DA, 1969, 531 NASA TM SUBRAMANYAN S, 1976, J ENG MATER TECH, V98, P316 TAIRA S, 1962, CREEP STRUCTURES WAREING J, 1981, FATIGUE ENG MAT STRU, V4, P131 WOODFORD DA, 1974, P INT C CREEP FAT EL NR 51 TC 9 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD JUN PY 2001 VL 24 IS 6 BP 405 EP 417 PG 13 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 469CM UT ISI:000170795800003 ER PT J AU Shlyannikov, VN Iltchenko, BV Stapanov, NV TI Fracture analysis of turbine disks and computational-experimental background of the operational decisions SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE gas-turbine failures; finite-element analysis; fracture damage; fatigue crack growth AB In this paper, fatigue crack growth under operation conditions for rotating disks of aircraft gas turbine engines is analyzed. Initiation and growth of surface cracks for compressor disks made from two-phase titanium alloy has occurred in a disk and blade attachment. Damage accumulation and growth for turbine disks made from steel took place on the inner surface of hole in a hub of wheel. Suggested approach of simulation modeling is used for an analysis and prevention of operation failures of engine rotating components. In the approach described, finite-element models (FEMs) in two and three dimensions were applied to the study of stress-strain state and stress intensity factors for the basic configurations of compressor and turbine disks and their operational damage. Proposed design modifications and repair technologies to existing in-service aircraft gas-turbine engine rotating components are analyzed and substantiated on a static strength and fatigue life basis. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Kazan Power Engn Inst, Kazan 420066, Russia. RP Shlyannikov, VN, Kazan Power Engn Inst, Krasnoselskaya Str 51, Kazan 420066, Russia. CR HUTCHINSON JW, 1968, J MECH PHYS SOLIDS, V16, P13 HUTCHINSON JW, 1968, J MECHANICS PHYSICS, V16, P337 NEWMAN JC, 1983, ASTM STP, V791, P238 RICE JR, 1968, J MECH PHYS SOLIDS, V16, P1 SHLYANNIKOV VN, 1993, PROBLEMS STRENGHT, V2, P65 SHLYANNIKOV VN, 1996, THEOR APPL FRACT MEC, V25, P187 SHLYANNIKOV VN, 1998, ECF 12, V1, P375 STEPANOV VN, 1985, INFORMATION I USSR S, V2, P95 NR 8 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD OCT PY 2001 VL 8 IS 5 BP 461 EP 475 PG 15 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 454HQ UT ISI:000169967500005 ER PT J AU Mann, BS Arya, V TI Abrasive and erosive wear characteristics of plasma nitriding and HVOF coatings: their application in hydro turbines SO WEAR LA English DT Article DE hydromachinery; HVOF coating; plasma nitriding; abrasion; high- and low-energy particle impingement wear ID SAND EROSION; BEHAVIOR; IMPACT AB This paper describes the abrasion and silt erosion characteristics of plasma nitriding and HVOF coatings along with commonly used steels in hydro turbines. For silt erosion characterisation, hydrofoils scaled down to 1/10 of the actual hydro turbine blade were selected. Angles of incidence, velocity and Reynolds numbers were maintained similar to those that commonly occur in hydro turbines, simulating low as well as high-energy impingement wear. The abrasive wear characterisation was carried out as per ASTM G-65. HVOF coated steel performed much better than plasma nitrided 12Cr and 13Cr-4Ni steels. Plasma nitrided 12Cr steel performed better than plasma nitrided 13Cr-4Ni steel. This is due to its higher microhardness and its ability to absorb more nitrogen under identical plasma nitriding experimental conditions. Based on this experimental study, HVOF and plasma nitrided 12Cr steel are being field-tried on a hydro turbine component, which is severely affected due to abrasion and silt erosion. (C) 2001 Elsevier Science B.V. All rights reserved. C1 BHEL, Corp R&D Div, Mat Sci Lab, Hyderabad 500093, Andhra Pradesh, India. RP Mann, BS, BHEL, Corp R&D Div, Mat Sci Lab, Hyderabad 500093, Andhra Pradesh, India. CR *MOD POW SYST, 1995, HYDR POW SC NATHP JH, P86 BARDAL E, 1993, P 10 EUR CORR C BARC BELL T, 1988, METALLIC INORGANIC C, P165 BROWNING JA, 1999, J THERM SPRAY TECHN, V8, P351 DEVI MU, 1998, SURF COAT TECH, V107, P55 HAUGEN K, 1995, WEAR, V186, P179 HAWTHORNE HM, 1999, WEAR 2, V225, P825 HOPPEL W, 1999, WEAR, V225, P1088 JACOBS L, 1999, J THERM SPRAY TECHN, V8, P125 KORHONEN AS, 1982, THIN SOLID FILMS, V90, P104 KORHONEN AS, 1982, THIN SOLID FILMS, V96, P103 LOVELOCK HLD, 1998, J THERM SPRAY TECHN, V7, P357 LOVELOCK HLD, 1998, J THERM SPRAY TECHN, V7, P97 LUGASCHEIDER E, 1997, THIN CHROMIUM COATIN, V2, P146 MANN BS, 1998, WEAR, V223, P110 MANN BS, 1999, WCPU GREEN POW 2 INT MANN BS, 2000, WEAR, V237, P140 MELLALI M, 1997, J THERM SPRAY TECHN, V6, P217 PODGORNIK B, 1999, WEAR, V232, P231 SALTZMANN GA, 1982, ASTM STP, V769, P71 SCHWETZKE R, 1999, J THERM SPRAY TECHN, V8, P433 SPALVINS T, 1987, 1 INT C ION NITR CLE, P202 STAINES AM, 1981, THIN SOLID FILMS, V86, P201 STEINER MS, 1999, MOL UROL, V3, P153 STEWART DA, 1998, SURF COAT TECH, V105, P13 WOOD R, 1994, P TASM SEA C CHRISTC, P19 WOOD RJK, 1997, WEAR, V211, P70 NR 27 TC 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUN PY 2001 VL 249 IS 5-6 BP 354 EP 360 PG 7 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 445WR UT ISI:000169482000004 ER PT J AU Yang, XH Dui, WZ TI Study of steam turbine blade degradation Part 1 - Degradation of mechanical properties of blade during service SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID FATIGUE THRESHOLD; FRACTURE; STEELS AB In this study, the mechanical properties of last stage 680 mm blades from a steam turbine with actual service lives of 10 years (70 000 h) and 20 years (120 000 h) have been systematically analysed by comparing them with a virgin blade. Experiment results show that the effect of service damage on the static tensile properties was weak, but the effect on fatigue fracture properties was remarkably strong. The fatigue limit and impact ductility had decreased by a little for the blade with a 10 year service life and by more for the one with a 20 year service life. The rate of fatigue crack propagation had increased a little for the blade with a 10 year service life and a lot for the one with a 20 year sevice life. The degradation of the fatigue and fracture behaviour of a blade is not linear. It rapidly gets worse at the later stage of service life. Observations of tensile and impact fracture in the blades by SEM show that the bound strength of the interface between dine carbides and the matrix weakened during long term service. Therefore, it has been proposed that the microstructure was weakened before the geometrical damage of the last stage. (C) 2001 IoM Communications Ltd. C1 Fuzhou Univ, Sch Mat Sci & Technol, Fuzhou 350002, Peoples R China. RP Yang, XH, Fuzhou Univ, Sch Mat Sci & Technol, Fuzhou 350002, Peoples R China. CR DU BP, 1997, J MECH STRENGTH, V19, P42 KADOYA Y, 1984, LIFE ASSESSMENT IMPR, P12 LEMAITRE J, 1986, ENG FRACT MECH, V25, P523 LI N, 1992, INT J FATIGUE, V14, P41 LI N, 1995, INT J FATIGUE, V17, P43 LIAW PK, 1991, METALL TRANS A, V22, P455 MCQUEEN HJ, 1977, METALL T A, V8, P833 PLUMTREE A, 1988, P C BAS QUEST FAT, V1, P81 YANG XH, 1996, J XJTU, V30, P94 YANG XH, 1997, ORDNANCE MAT SCI ENG, V20, P7 NR 10 TC 0 PU I O M COMMUNICATIONS LTD INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0267-0836 J9 MATER SCI TECHNOL JI Mater. Sci. Technol. PD MAY PY 2001 VL 17 IS 5 BP 551 EP 555 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 439UA UT ISI:000169134900012 ER PT J AU Yang, XH Dui, WZ TI Study of steam turbine blade degradation Part 2 - Damage mechanical model of blade materials during long term service SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID CYCLE FATIGUE; FRACTURE AB A damage mechanical model has been proposed from the theory of continuum damage mechanics that describes the service damage evolution of steam turbine blade materials during long term service. In the model, the damage variable is selected according to the variation in fatigue limit of the blade materials after service. Furthermore, a model of the degradation of fatigue strength during service has been created. The experimental results are in good agreement with the model. Compared with the low cycle fatigue damage model, the strength design of the blade is conservative early in its service life. If the degradation in fatigue strength is not taken into account, the life prediction of the blade is inadequate for long term service lives. (C) 2001 IoM Communications Ltd. C1 Fuzhou Univ, Sch Mat Sci & Technol, Fuzhou 350002, Peoples R China. RP Yang, XH, Fuzhou Univ, Sch Mat Sci & Technol, Fuzhou 350002, Peoples R China. CR CHABOCHE JL, 1981, NUCL ENG DES, V64, P233 CHABOCHE JL, 1988, FATIGUE FRACT ENG M, V11, P1 JANSON J, 1977, J APPL MECH, V44, P69 KACHANOV LM, 1958, IZV AKAD NAUK USS TN, V8, P26 LEMAITRE J, 1984, NUCL ENG DES, V80, P233 LEMAITRE J, 1985, J ENG MATER-T ASME, V107, P83 LEMAITRE J, 1986, ENG FRACT MECH, V25, P523 LEMAITRE J, 1990, MECH SOLID MAT MANSON SS, 1986, ENG FRACT MECH, V25, P539 NING A, 1997, THESIS XIAN JIAOTONG ROBOTNOV YN, 1969, CREEP PROBLEMS STRUC SHI M, 1993, ENG FRAC MECH, V46, P393 YANG XH, 1997, INT J FATIGUE, V19, P687 YANG XH, 1998, J MECH STRENGTH, V20, P287 NR 14 TC 0 PU I O M COMMUNICATIONS LTD INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0267-0836 J9 MATER SCI TECHNOL JI Mater. Sci. Technol. PD MAY PY 2001 VL 17 IS 5 BP 556 EP 558 PG 3 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 439UA UT ISI:000169134900013 ER PT J AU Willett, FT Bergles, AE TI Heat transfer in rotating narrow rectangular ducts with heated sides oriented at 60 degrees to the r-z plane SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article ID 2-PASS SQUARE CHANNEL; SMOOTH WALLS; MODEL ORIENTATION; RIB TURBULATORS; FLOW AB Gas turbine blade life is often limited by the effectiveness of the cooling in the trailing edge convective cavity, which generally has a narrow cross-section. Previous research on rotational effects considered cavity shapes quite different from those of typical trailing edge cavities. In this research, experiments were conducted to deter-mine the effect of rotation on heat transfer in ducts of narrow cross-section (height-to-width ratio of 1:10), oriented with the heated sides at 60 degrees to the r-z plane. in the experiment, a high-molecular-weight gas (Refrigerant- 134A) at ambient pressure and temperature conditions was used to match the dimensionless parameters at engine conditions. Thin foil heaters were used to produce a constant hear flux at the long sides of the duct; the narrow sides were unheated. Duct Reynolds numbers were varied np to 20,000; rotation numbers were varied rep to 0.25. The rest results show the effect of rotation and aspect ratio on duct leading and trailing side heat transfer. In addition, the results shaw the variation in heat transfer coefficient with transverse location in the duct, demonstrating the effect of rotation not only on lead and trail side heat transfer, but also on forward and aft end heat transfer. C1 Rensselaer Polytech Inst, Troy, NY 12180 USA. GE Power Syst, Schenectady, NY USA. RP Willett, FT, Rensselaer Polytech Inst, Troy, NY 12180 USA. CR DUTTA S, 1995, J HEAT TRANS-T ASME, V117, P1058 HAN JC, 1993, J HEAT TRANS-T ASME, V115, P912 HAN JC, 1994, J TURBOMACH, V116, P149 JOHNSON BV, 1990, 90GT331 ASME KAYS WM, 1980, CONVECTIVE HEAT MASS KLINE SJ, 1953, MECH ENG, P3 KUO CR, 1994, 5 INT S TRANSP PHEN MOCHIZUKI S, 1994, J TURBOMACH, V116, P133 MORI Y, 1971, INT J HEAT MASS TRAN, V14, P1807 MORRIS WD, 1998, AERONAUT J, V102, P277 PARK CW, 1998, J HEAT TRANS-T ASME, V120, P624 PARSONS JA, 1994, INT J HEAT MASS TRAN, V37, P1411 PARSONS JA, 1995, INT J HEAT MASS TRAN, V38, P1151 SOONG CY, 1991, ASME, V113, P604 WAGNER JH, 1989, 89GT272 ASME WILLETT FT, 1999, THESIS RENSSELAER PO ZHANG N, 1993, J HEAT TRANS-T ASME, V115, P560 NR 17 TC 9 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD APR PY 2001 VL 123 IS 2 BP 288 EP 295 PG 8 SC Engineering, Mechanical GA 439XG UT ISI:000169142400014 ER PT J AU Arakere, NK Moroso, J TI Fatigue failure in high-temperature single crystal superalloy turbine blades SO HIGH TEMPERATURE MATERIALS AND PROCESSES LA English DT Article DE fatigue; single crystals; PWA1480; PWA1484; crystal orientation; superalloys; face centered cubic (FCC); turbine blades; blade attachments; fretting AB Fatigue failures in PWA1480/1493 single crystal nickel-base superalloy turbine blades used in the Space Shuttle Main Engine fuel turbopump are discussed. Many blades in the turbopump had small HCF cracks initiating from the leading edge radius and extending across the airfoil tip on the pressure side. Stage Ii noncrystallographic fatigue cracks with multiple origins were present at the core leading edge radius and extending down the airfoil span along the core surface. The longer cracks transitioned from stage II fatigue to crystallographic stage I fatigue propagation, on octahedral planes. Reasons that contributed to initiation and growth of tip cracks were the small leading edge fillet radius, the non-uniform wail thickness on pressure and suction sides, the high mean stress, and consequently low allowable alternating stress. Many blades also showed fatigue damage in the attachment regions leading to fretting induced cracking with multiple origins with stage II cracks. An investigation of crack depths on the population of blades as a function of secondary crystallographic orientation revealed that for beta = 45 +/- 15 degrees tip cracks arrested after some growth or did not initiate at all. Detailed 3D FE stress analysis of AHPFTP/AT SSME single crystal turbine blades subjected to rotational, aerodynamic, and thermal loads was conducted. Evaluation of stress response at the blade tip and attachment regions, as a function of primary and secondary crystal orientation, revealed that there are preferential beta orientations for which crack growth is minimized at the blade tip. The FE analysis results give further evidence to the conclusion that control of secondary and primary crystallographic orientation has the potential to significantly increase a component's resistance to fatigue crack growth without adding additional weight or cost. Fretting contact stresses in the attachment region were seen to reach peak values at locations where fretting cracks have been observed. Contact stresses at critical attachment regions also varied significantly as a function of crystal orientation alone. The tangential normal stress ox in the attachment region increased with increasing coefficient of friction at the critical contact location. This is of practical interest since cracks are thought to initiate at locations where sigma (x) reaches a maximum tensile value, and hence high temperature metal coatings applied to the attachment region, to reduce the coefficient of friction, will be beneficial in enhancing fretting fatigue life. Additional fretting damage parameters need to be evaluated in detail for single crystal materials. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. Pratt & Whitney Govt Engines & Space Propuls Grp, W Palm Beach, FL 33418 USA. RP Arakere, NK, Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. CR ARAKERE NK, 2000, ASME IGTI C MAY 8 11 ATTIA MH, 1992, STP, V1159 COWLES BA, 1996, INT J FRACTURE, P1 CUNNINGHAM S, 1994, WLTR964048, V2 CUNNINGHAM S, 1996, WLTR944089, V1 DELUCA DP, COMMUNICATION DELUCA DS, 1995, FR23800 OFF NAV RES GIANNOKOPOULOS, 1999, ACTA MAT HILLS DA, 1994, MECH FRETTING FATIGU HOEPPNER DW, 1990, ASTM, P23 KEAR BH, 1967, T AIME, V239, P1209 MCLEAN M, 1983, DIRECTIONALLY SOLIDI, P151 MOROSO J, 1999, THESIS U FLORIDA GAI PRATT, 1996, FR245811 PW PRATT, 1998, SSME AT HPFTP 1 STAG SWANSON G, UNPUB NASA TECHNICAL SZOLWINSKI MP, 1996, WEAR, V198, P93 TELESMAN J, 1995, INT GAS TURB AER C E VERSNYDER FL, 1960, T ASM, V52, P485 VINGSBO O, 1988, WEAR, V126, P131 NR 20 TC 1 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6455 J9 HIGH TEMP MATER PROCESS JI High Temp. Mater. Process. PD MAY PY 2001 VL 20 IS 2 BP 117 EP 135 PG 19 SC Materials Science, Multidisciplinary GA 434MU UT ISI:000168820100004 ER PT S AU Shen, MHH Nicholas, T TI Reliability high cycle fatigue design of gas turbine blading system using probabilistic Goodman diagram SO PROBABILISTIC METHODS IN FATIGUE AND FRACTURE SE KEY ENGINEERING MATERIALS LA English DT Article DE fatigue; Goodman diagram; probability theory AB A framework for the probabilistic analysis of high cycle fatigue is developed. The framework will be useful to U.S. Air Force and aeroengine manufacturers in the design of high cycle fatigue in disk or compressor components fabricated from Ti-6A1-4V under a range of loading conditions that might be encountered during service, The main idea of the framework is to characterize vibratory stresses from random input variables due to uncertainties such as crack location, Loading, material properties, and manufacturing variability. The characteristics of such vibratory stresses are portrayed graphically as histograms, or probability density function (PDF). The outcome of the probability measures associated with all the values of a random variable exceeding the material capability is achieved by a failure function g(X) defined by the difference between the vibratory stress and Goodman line or surface such that the probability of HCF failure is P-f=P(g(X<0)), Design can then be based on a go-no go criterion based on an assumed risk, The framework can be used to facilitate the development of design tools for the prediction of inspection schedules and reliability in aeroengine components. Such tools could lead ultimately to improved life extension schemes in aging aircraft, and more reliable methods for the design and inspection of critical components. C1 Ohio State Univ, Dept Aerosp Engn & Aviat, Columbus, OH 43210 USA. USAF, Res Lab, MLLN, Wright Patterson AFB, OH 45433 USA. RP Shen, MHH, Ohio State Univ, Dept Aerosp Engn & Aviat, Columbus, OH 43210 USA. CR CHIANG HWD, 1993, J TURBOMACH, V115, P762 HASOFER AM, 1974, J ENG MECH DIV ASCE, V100, P111 MAXWELL DC, 1999, ASTM STP, V1321, P626 MCDOWELL DL, 1996, INT J FRACTURE, V80, P103 NICHOLAS T, 1996, INT J FRACTURE, V80, P219 SHEN MHH, 1996, P SOC PHOTO-OPT INS, V2720, P240 SHEN MHH, 1998, 3 NAT TURB ENG HIGH ZABIEREK DW, 1998, 3 NAT TURB ENG HIGH NR 8 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2001 VL 200 BP 139 EP 159 PG 21 SC Materials Science, Ceramics; Materials Science, Composites GA BS10N UT ISI:000168666800007 ER PT J AU Tsao, TP Lin, CH TI The effects of a field choke coil on the operating life of steam turbine shafts and blades SO ELECTRIC POWER COMPONENTS AND SYSTEMS LA English DT Article DE turbine shafts and blades; fatigue life expenditure; choke coil; electromagnetic torque (E/M torque) ID TORSIONAL FATIGUE; GENERATOR SHAFTS; OSCILLATIONS AB Due to many factors, it has become very difficult to implement new power plants, such as land acquisition and environment protection, etc. Consequently, it gathers more and more attention about how to extend operating life of the existing generator units. As a part of a generator-life extension program, the effects of a choke coil on the fatigue life of turbine shafts and blades are studied for a practical turbine-generator system. It is found that the field choke coil has the capability of suppressing E/M disturbing torque during fault, clearing and reclosing periods, which would substantially alleviate impacts into turbine system and reduce torque vibrations on shafts and blades accordingly. Based on a three-year project of General Electric Co., the fatigue life expenditures of shafts and blades are evaluated. It is shown that the life loss on shaft and blade sections can be considerably reduced with the proposed field choice coil in service. C1 Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. RP Tsao, TP, Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. CR CHYN C, 1996, IEE P-GENER TRANSM D, V143, P479 CUDWORTH CJ, 1990, IEE PROC-C, V137, P327 ELSERAFI AM, 1986, ELECT MACHINES POWER, P4517 FARIED SO, 1996, IEE P-GENER TRANSM D, V143, P487 LEE YS, 1991, IEE PROC-C, V138, P419 PADIYAR KR, 1991, IEEE T POWER SYST, V6, P458 PERKINS BK, 1997, IEEE T POWER SYST, V12, P1619 PLACEK RJ, 1984, EL3083 EPRI USU YY, 1989, IEE P C, V136, P78 WANG HF, 1997, INT J ELEC POWER, V19, P1 WASYNCZUK O, 1981, IEEE T PAS, V100, P3340 WILLIAMS RA, 1986, IEEE T ENERGY CONVER, V1, P80 NR 12 TC 0 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1532-5008 J9 ELECTR POWER COMPON SYST JI Electr. Power Compon. Syst. PD JAN PY 2001 VL 29 IS 1 BP 41 EP 53 PG 13 SC Engineering, Electrical & Electronic GA 428QK UT ISI:000168472200004 ER PT J AU Arakere, NK Swanson, G TI Fretting stresses in single crystal superalloy turbine blade attachments SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article DE fretting; fatigue; high cycle fatigue (HCF); single crystal; crystal orientation; nickel-base superalloy; face centered cubic (FCC); turbine blade; blade attachment ID FATIGUE; MECHANICS AB Single crystal nickel base superalloy turbine blades are being utilized in rocket engine turbopumps and turbine engines because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. High cycle fatigue induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Blade attachment regions are prone to fretting fatigue failures. Single crystal nickel base superalloy turbine blades are especially prone to fretting damage because the subsurface shear stresses induced by fretting action at the attachment regions ran result in crystallographic initiation and crack growth along octahedral planes. This paper presents contact stress evaluation in the attachment region for single crystal turbine blades used in the NASA alternate advanced high pressure fuel turbo pump for the space shuttle main engine. Single crystal materials have highly anisotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. Blades and the attachment region are modeled using a large-scale three-dimensional finite element model capable of accounting for contact friction, material anisotropy, and variation in primary and secondary crystal orientation. Contact stress analysis in the blade attachment regions is presented as a function of coefficient of friction and primary and secondary crystal orientation, Fretting stresses at the attachment region are seen to vary significantly as a function of crystal orientation. The stress variation as a function of crystal orientation is a direct consequence of the elastic anisotropy of the material. Fatigue life calculations and fatigue failures are discussed for the airfoil and the blade attachment regions. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NASA, George C Marshall Space Flight Ctr, Strength Anal Grp ED22, Huntsville, AL 35812 USA. RP Arakere, NK, Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. CR *PRATT WHITN, 1996, FR245811 P W ARAKERE NK, 2000, NASTTP210074 ARAKERE NK, 2000, P ASME IGTI C MUN GE ATTIA MH, 1992, ASTM PUBLICATION BANANTINE JA, 1985, ASTM S LOW CYCL FAT COWLES BA, 1996, INT J FRACTURE, P1 DELUCA D, 1995, FR23800 OFF NAV RES DELUCA DP, COMMUNICATION DELUCA DP, 1989, HYDROGEN EFFECTS MAT DOMBROMIRSKI J, 1990, STANDARDIZATION FRET, P60 FATEMI A, 1988, FATIGUE FRACT ENG M, V11, P149 GELL M, 1986, PROCESSING PROPERTIE, P41 GIANNAKOPOULOS AE, 1998, ACTA MATER, V46, P2955 HILLS DA, 1994, MECH FRETTING FATIGU HOEPPNER DW, 1990, STANDARDIZATION FRET, P23 JOHN R, 1998, MIXED MODE CRACK BEH KANDIL FA, 1982, BIAXIAL LOW CYCLE FA, P203 LEKHNITSKII SG, 1963, THEORY ELASTICITY AN MOROSO J, 1999, THESIS U FLORIDA GAI RUIZ C, 1984, EXP MECH, V24, P208 SAYYAH T, 1999, 62102599001 NASA SIMS CT, 1987, SUPERALLOYS, V2, P1 SMITH KN, 1970, J MATER, V5, P767 SOCIE DF, 1985, 2 INT S MULT FAT SHE STOUFFER DC, 1996, INELASTIC DEFORMATIO SZOLWINSKI MP, 1996, WEAR, V198, P93 TELESMAN J, 1989, ENG FRACT MECH, V34, P1183 VERSNYDER FL, 1960, T ASM, V52, P485 VINGSBO O, 1988, WEAR, V126, P131 NR 29 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4787 J9 J TRIBOL-TRANS ASME JI J. Tribol.-Trans. ASME PD APR PY 2001 VL 123 IS 2 BP 413 EP 423 PG 11 SC Engineering, Mechanical GA 426HM UT ISI:000168343800026 ER PT J AU Gaumann, M Bezencon, C Canalis, P Kurz, W TI Single-crystal laser deposition of superalloys: Processing-microstructure maps SO ACTA MATERIALIA LA English DT Article DE Ni alloy; single crystal; solidification; laser treatment ID RAPID SOLIDIFICATION; DIRECTIONAL SOLIDIFICATION; PREDICTION; COLUMNAR; NUCLEATION; WELDS; GRAIN AB In order to extend the life cycle of modern single-crystal (SX) high-pressure high-temperature gas turbine blades, repair of cracked or worn parts is of great interest. The success of the repair technique depends critically on a close process control in order to ensure SX repair. Based on solidification theory a process called epitaxial laser metal forming (E-LMF) has been developed. This paper presents the important concepts necessary for any process control for SX repair based on processing maps which relate the expected solidification microstructures and growth morphologies to the processing conditions. These maps are obtained in two steps. Firstly, the relationships between local solidification conditions and the resulting solidification microstructures, i.e. columnar or equiaxed, art: formulated. Secondly, the local solidifiuation conditions as a function of the laser processing parameters are calculated with an analytical hear flux model. By a combination of both approaches, processing-microstructures map are obtained which define processing windows for SX generation and repair by laser deposition. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. C1 Swiss Fed Inst Technol, Dept Mat, CH-1015 Lausanne, Switzerland. RP Kurz, W, Swiss Fed Inst Technol, Dept Mat, CH-1015 Lausanne, Switzerland. CR ADAMS BL, 1993, METALL TRANS A, V24, P819 BODADILLA M, 1988, J CRYST GROWTH, V89, P531 BUSSAC A, 1991, MATER SCI ENG, V237, P35 CANALIS P, IN PRESS SINGLE CRYS CLINE HE, 1977, J APPL PHYS, V48, P3895 DAVID SA, 1989, INT MATER REV, V34, P213 DAVID SA, 1997, SCI TECHNOL WELD JOI, V2, P79 DEBROY T, 1995, MATH MODELLING WELD, V2, P3 ERICKSON GL, 1994, MAT ADV POWER ENG, P1055 FRENK A, 1991, METALL TRANS B, V22, P139 FRENK A, 1997, METALL MATER TRANS B, V28, P501 GARTNER F, 1997, ACTA MATER, V45, P51 GAUMANN M, 1997, MAT SCI ENG A-STRUCT, V226, P763 GAUMANN M, 1999, MAT SCI ENG A-STRUCT, V271, P232 GEBHARDT A, 1996, RAPID PROTOTYPING WE GEISSLER E, 1987, OPTO ELEKTRONIK MAGA, V3, P430 GREMAUD M, 1996, SURF ENG, V12, P251 HARRIS K, 1992, SUPERALLOYS 1992, P297 HENRY S, IN PRESS MAT SCI ENG HUNT JD, 1984, MATER SCI ENG, V65, P75 KURZ W, 1986, ACTA METALL, V34, P823 KURZ W, 1994, MAT SCI ENG A-STRUCT, V179, P46 KURZ W, 1995, MATH MODELLING WELD, P40 KURZ W, 1998, FUNDAMENTALS SOLIDIF MURPHY ML, 1994, LAS MAT PROC C ICALE, V79, P31 PICASSO M, 1991, NUMERICAL METHODS TH, V7, P199 PICASSO M, 1994, METALL MATER TRANS B, V25, P281 RAPPAZ M, 1990, METALL TRANS A, V21, P1767 RAPPAZ M, 1996, METALL MATER TRANS A, V27, P695 RAPPAZ M, 1999, ACTA MATER, V47, P3205 ROSENTHAL D, 1946, T ASME, V68, P849 SAUNDERS N, 1996, SUPERALLOYS 1996, P101 SHAO G, 1994, ACTA METALL MATER, V42, P2937 STEIGERWALD EA, 1994, J MAT ED, V16, P21 THOMA DJ, 1996, ADV LASER PROCESSING THORNTON PH, 1970, METALL T, V1, P207 VERSNYDER FL, 1970, MATER SCI ENG, V6, P213 VITEK JN, 1997, SCI TECHNOL WELD JOI, V2, P109 WANG CY, 1994, METALL MATER TRANS A, V25, P1081 WRIGHT SI, 1992, METALL TRANS A, V23, P759 NR 40 TC 40 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD APR 2 PY 2001 VL 49 IS 6 BP 1051 EP 1062 PG 12 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 420WF UT ISI:000168027700012 ER PT J AU Younsi, R El-Batanony, I Tritsch, JB Naji, H Landjerit, B TI Dynamic study of a wind turbine blade with horizontal axis SO EUROPEAN JOURNAL OF MECHANICS A-SOLIDS LA English DT Article DE finite elements method; dynamic of structures; Newmark method; beam theory; aerodynamic efforts; gust of wind; Bezier surfaces ID AIRFOIL AB The study of the dynamic behavior of a wind turbine with horizontal axis can be undertaken by various methods of analysis. The effects of the change of the aerodynamic flow (in the steady and unsteady cases), the variation of parameters of the cinematic movement (angle of attack, pitch angle and yaw angle) and the definition of subsystems characteristics that makes the wind turbine (blade, nacelle and pylon) allow one to characterize the structural dynamic behavior of the wind turbine. It is therefore necessary to develop these items. Once this is done, the structural dynamic behavior of the system can be improved. The term 'improve' means the increase of the life duration by mastering the fatigue effects and the reduction of cost without sacrificing the aerodynamic output. The present study aims to examine the behavior of the blade, which is the main part of the wind turbine in that it that transmits forces to all other parts of the structure. The model is based on the theory of three-dimensional beams, under the assumption of variable sections of the type NACA 4415 airfoil, and takes into account membrane, transversal shear, flexion and free torsion effects. With regards to the aerodynamic loads (the lift, the drag and the pitching moment), a validation has been undertaken by considering experimental data and numerical results obtained by a CFD code (Fluent). The forces are obtained by means of a parametric CAD method interpolation of the aerodynamic poles by Bezier patch under geometrical constraints solved by a Simplex type algorithm. The emphasis is put on dynamic aspects by a complete processing of the dynamic equilibrium equation, applied to the wind turbine blade with horizontal axis. (C) 2001 Editions scientifiques et medicales Elsevier SAS. C1 EUDIL, Dept Mecan, LML, CNRS,URA 1441, F-59655 Villeneuve Dascq, France. RP Landjerit, B, EUDIL, Dept Mecan, LML, CNRS,URA 1441, Bd Paul Langevin,Cite Sci, F-59655 Villeneuve Dascq, France. CR BATHE KJ, 1982, FINITE ELEMENT PROCE BATOZ JL, 1990, MODELISATION STRUCTU, V1 BATOZ JL, 1990, MODELISATION STRUCTU, V2 BEZIER P, 1987, MATH CAO, V4 BJORCK A, 1995, TN31 FFA CHRISTENSEN HF, 1995, R826EN RIS NAT LAB DHATT G, 1984, UNE PRESENTATION MET GUILMINEAU E, 1999, AIAA J, V37, P128 HOFFMANN MJ, 1994, WINDPOWER 94 AWEA MI, P583 KAISER K, 1996, IMECHE, P187 KENNETH T, 1993, LOADS DYNAMICS STALL LEE CW, 1996, J SOUND VIB, V192, P439 LINDLEY D, 1986, P I CIVIL ENG, V80, P969 PALUCH B, 1991, 17 EUR ROT FOR DGLR ROGERS DA, 1990, MATH ELEMENTS COMPUT SHIPLEY DE, 1994, WINDPOWER AWEA MINN, P615 SPERA DA, 1995, WIND TURBINE TECHNOL TCHON KF, 1994, J FLUID ENG-T ASME, V116, P870 THRESHER RW, 1986, ASME, V107, P17 VERON M, 1989, CONV HERMES CFAO HER WRIGHT AD, 1994, WINDPOWER AWEA MINN, P813 NR 21 TC 1 PU GAUTHIER-VILLARS/EDITIONS ELSEVIER PI PARIS PA 23 RUE LINOIS, 75015 PARIS, FRANCE SN 0997-7538 J9 EUR J MECH A-SOLID JI Eur. J. Mech. A-Solids PD MAR-APR PY 2001 VL 20 IS 2 BP 241 EP 252 PG 12 SC Mechanics GA 413PX UT ISI:000167621900005 ER PT J AU Brown, JA Freer, R Rowley, AT TI Reconditioning of gas turbine components by heat treatment SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID CREEP AB At the high operating temperatures experienced within a gas turbine, creep damage is a major life-limiting factor. This is especially true for components which are highly stressed and closest to the hat gas inlet end of the machine, such as the rotating blades in this area. The ability to recover the creep properties of used gas turbine components might enable their service lives to be increased consider-ably. Thereby, maintenance costs could heat treatment will be reviewed and perceived limitations identified. The current work will be reduced. Previous research into the feasibility of reconditioning crept superalloys by add to knowledge on the effects of conventional recovery techniques and will explore potential new heat treatment regimes. The experimental and analytical methods to be used will be both described and supported by preliminary results. C1 UMIST, Postgrad Training Partnership, Chester CH1 6ES, Cheshire, England. Univ Manchester, Inst Sci & Technol, Ctr Mat Sci, Manchester M1 7HS, Lancs, England. EA Technol Ltd, Chester CH1 6ES, Cheshire, England. RP Brown, JA, UMIST, Postgrad Training Partnership, Chester CH1 6ES, Cheshire, England. CR BALDAN A, 1992, J MATER SCI LETT, V11, P1319 BRUCE RW, 1988, MATERIALS RES SOC S, V124, P3 CINA B, 1976, 2 INT C MECH BEH MAT, P2025 DAVIES PW, 1966, J I MET, V94, P270 DAVIES PW, 1967, J I MET, V95, P231 DAVIES PW, 1973, J I MET, V101, P153 DAVIES PW, 1975, MET SCI, V9, P319 DENNISON JP, 1978, MATER SCI ENG, V33, P35 EVANS RW, CREEP METALS ALLOYS GIRDWOOD RB, 1996, INT J PRES VES PIP, V66, P141 HART RV, 1968, J I MET, V96, P338 HOCHMAN RF, 1988, ADVAN MATER PROCESS, V134, P36 KOUL AK, 1988, SUPERALLOYS 1988, P755 MCLEAN M, 1984, P 5 INT S SUP MET SO, P73 NABARRO FRN, 1995, PHYSICS CREEP ROSS MD, 1979, REJUVENATION TURBINE STEVENS RA, 1979, ACTA METALL, V27, P67 STEVENS RA, 1979, P 5 INT C STRENGTH M, V1, P27 WROE R, 1996, J MATER SCI, V31, P2019 ZAVALISHIN YK, 1995, SURF ENG APPL ELECTR, V2, P65 NR 20 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2001 VL 123 IS 1 BP 57 EP 61 PG 5 SC Engineering, Mechanical GA 413CC UT ISI:000167591500008 ER PT J AU Kurz, R Brun, K TI Degradation in gas turbine systems SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Any prime mover exhibits the effects of weal and tear over time. The problem of predicting the effects of wear and tear on the performance of any engine is still a matter of discussion. Because the function of a gas turbine is the result of the fine-tuned cooperation of many different components, the emphasis of this paper is on the gas turbine and its driven equipment (compressor or pump) as a system, rather than on isolated components. We, will discuss the effect of degradation on the package as part of a complex system (e.g., a pipeline, a reinjection station, etc.). Treating the gas turbine package as a system reveals the effects of degradation on the match of the components as well as on the match with the driven equipment. This article will contribute insights into the problem of gas turbine system degradation. Based on some detailed studies on the mechanisms that cause engine degradation, namely, changes in blade surfaces due to erosion or fouling, and the effect on the blade aerodynamics; changes in seal geometries and clearances, and the effect on parasitic flows; and changes in the combustion system (e.g., which result in different pattern factors), the effects of degradation will be discussed The study includes a methodology to simulate the effects of engine and driven equipment degradation. With a relatively simple set of equations that describe the engine behavior and a number of linear deviation factors which can easily be obtained from engine maps or test delta, the equipment behavior for various degrees of degradation will be studied. A second model, using a stage by stage model for the engine compressor, is used to model the compressor deterioration. The authors have avoided to present figures about the speed of degradation, because it is subject to a variety of operational and design factors that typically cannot be controlled entirely. C1 Solar Turbines Inc, San Diego, CA 92123 USA. RP Kurz, R, Solar Turbines Inc, San Diego, CA 92123 USA. CR AKER GF, 1988, 88GT206 ASME BAKKEN LE, 1996, 96GT273 ASME BAMMERT K, 1965, 164 VIK BAMMERT K, 1967, ARCH EISENHUTTENWES, V38, P287 BOELCS A, 1988, ASME, V110, P512 BOYLE RJ, 1994, J TURBOMACH, V116, P745 BRUN K, 1998, 98GT1 ASME COHEN H, 1996, GAS TURBINE THEORY DIAKUNCHAK IS, 1991, 91GT228 ASME ELROD WC, 1990, 90GT208 ASME FRITH PC, 1992, 92GT83 ASME HAQ IU, 1998, 98GT53 ASME KHALID SA, 1998, 98GT188 ASME KIND RJ, 1996, 96GT203 ASME KURZ R, 1991, P 10 ISABE NOTT KURZ R, 1995, INT ROTATING MACHINE, V2, P59 MACLEOD JD, 1991, 91GT41 ASME MILSCH R, 1971, THESIS U HANNOVER PINSON M, 1994, 94GT326 ASME RADTKE F, 1980, 361 VDI SCHMIDT KJ, 1992, EXPT THEORETISCHE UN SHABBIR A, 1997, 97GT346 ASME SINGH D, 1996, 96GT422 ASME SPAKOVSZKY ZS, 1999, 99GT439 ASME STALDER JP, 1998, 98GT420 ASME TARABRIN AP, 1998, 98GT416 ASME TRAUPEL W, 1988, THERMISCHE TURBOMASC NR 27 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2001 VL 123 IS 1 BP 70 EP 77 PG 8 SC Engineering, Mechanical GA 413CC UT ISI:000167591500010 ER PT J AU Woodford, DA TI Stress relaxation testing of service exposed IN738 for creep strength evaluation SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID SILICON-NITRIDE; DESIGN ANALYSIS AB Standard size and miniature specimens of IN738 were taken from a service exposed turbine blade and vane for comparative stress relaxation testing at 800C, 850C, and 900C. Base darn taken from root section material were used to construct stress versus creep rare parametric curves which could be used directly in design. Up to five decades in creep rates were obtained at each temperature from rests lasting less than one day, The darn were also presented in the form of stress versus predicted times to 0.5 percent creep which compared well with available long rime creep data. Differences were noted in specimens taken from different locations in the airfoil regions which probably resulted from differences in grain size or orientation, Based on these measurements it was concluded that there was no significant effect of section size on creep strength as defined by this test, and that the alloy was quite insensitive to prior deformation and thermal exposures. A life management procedure. using a combination of creep strength evaluation based on the stress relaxation test and a separate fracture evaluation measurement, is outlined in which end of useful life is defined in terms of minimum acceptable performance levels. C1 Mat Performance Anal Inc, Santa Barbara, CA 93101 USA. RP Woodford, DA, Mat Performance Anal Inc, 1707 Garden St, Santa Barbara, CA 93101 USA. CR GRWZWINSKI GG, 1995, POLYM ENG SCI, V35, P1931 HARRISON GF, 1973, C222 I MECH ENG OXX G, 1973, C212 I MECH ENG REIF SK, 1995, MATER DESIGN, V16, P15 WOODFORD DA, 1993, MATER DESIGN, V14, P231 WOODFORD DA, 1996, MATER DESIGN, V17, P127 WOODFORD DA, 1997, ADV TURBINE MAT DESI, P613 WOODFORD DA, 1997, MATER HIGH TEMP, V14, P413 WOODFORD DA, 1998, J AM CERAM SOC, V81, P2327 NR 9 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 2000 VL 122 IS 3 BP 451 EP 456 PG 6 SC Engineering, Mechanical GA 404QG UT ISI:000167111600012 ER PT J AU Goldfine, N Sheiretov, Y Washabaugh, A Zilberstein, V Kenny, S Crowther, P TI Materials characterisation and flaw detection for metallic coating repairs SO INSIGHT LA English DT Article AB Repairs of overlay coatings and Thermal Barrier Coatings (TBCs) extend the life of coated components, such as turbine blades. Characterisation of the coatings and substrates, as well as detection of cracks and other types of degradation, is critical to repair decisions and activities. If blade and coating integrity is determined to be acceptable, the blades can remain in service, resulting in substantial cost savings. The capability to measure the thickness of the remaining non-degraded part of overlay coatings or metallic bond coat, together, with porosity and ceramic topcoat thickness, is required for repair qualification or to ensure efficient and complete stripping of the coatings, without compromising the substrate. A conformable eddy current sensor and 'GridStation' measurement system are described that permit independent/ simultaneous measurement of three unknown; in the case of TBCs they include ceramic top coat thickness, metallic bond coat porosity, and metallic bond coat thickness. With a further enhancement of this capability, now in progress applications will include in-service inspections of land-based turbine overlay coatings, inspections of TBCs, and inspections of other high-performance functional coating systems in the electronics, energy and manufacturing, as well as aerospace markets. C1 JENTEK Sensors Inc, Watertown, MA 02472 USA. Innogy Ltd, Swindon SN5 6PB, Wilts, England. RP Goldfine, N, JENTEK Sensors Inc, 200 Dexter Ave, Watertown, MA 02472 USA. CR AULD BA, 1999, J NONDESTRUCTIVE EVA, V18 GOLDFINE N, 1998, ASM INT GAS TURB TEC GOLDFINE NJ, FALL 1994 AM SOC NDT GOLDFINE NJ, 1993, MAT EVAL MAR, P396 GOLDFINE NJ, 1995, SPIE C NOND EV AG IN MILLER RA, 1997, J THERM SPRAY TECHN, V6, P35 NR 6 TC 2 PU BRITISH INST NON-DESTRUCTIVE TESTING PI NORTHAMPTON PA 1 SPENCER PARADE, NORTHAMPTON NN1 5AA, NORTHANTS, ENGLAND SN 1354-2575 J9 INSIGHT JI Insight PD DEC PY 2000 VL 42 IS 12 BP 809 EP 814 PG 6 SC Instruments & Instrumentation; Materials Science, Characterization & Testing GA 404MB UT ISI:000167101200020 ER PT J AU Ciavarella, M Demelio, G TI A review of analytical aspects of fretting fatigue, with extension to damage parameters, and application to dovetail joints SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE contact stresses; fretting fatigue; high cycle fatigue; crack initiation; fretting damage; turbine blades; dovetail joints; gas turbine engines ID PLANE CONTACT PROBLEM; PARTIAL SLIP; FRACTURE-MECHANICS; CRACK INITIATION; FLAT; INDENTATION; PROPAGATION; METHODOLOGY; PREDICTION; ARREST AB Recent advances by the authors in analytical methods for the analysis of plane fretting fatigue (FF) contact problems are described, acid new consequences for FF damage are derived. Constant normal load and oscillating tangential load (the celebrated Cattaneo-Mindlin case) are considered with in-phase oscillating moderate bulk stresses, for an arbitrary spline rotated geometry and, in particular, the flat punch with rounded corners in view of application to the dovetail joints. Extremely simple, new results are found for initiation parameters such as tangential microslip and frictional energy, which have been used under certain conditions as threshold parameters for FF. Finally, it is shown that for an "almost flat" geometry, the surface damage parameters decrease, but the tensile stress concentration increases, although it becomes more localized, suggesting that for cracks eventually initiated, the likelihood of self-arrest is higher than in the equivalent Hertzian case with same loads. This seems to interpret recent experiments, although it is not clear whether the optimal geometry in terms of FF life is the perfectly hat one, or an intermediate one. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 CNR, IRIS, COMES, I-70126 Bari, Italy. Politecn Bari, DPPI, I-70126 Bari, Italy. RP Ciavarella, M, CNR, IRIS, COMES, Str Crocefisso 2-B, I-70126 Bari, Italy. CR ARAUJO JA, 1999, INT J FATIGUE, V21, P947 ARCHARD JF, 1957, P ROY SOC LOND A MAT, V243, P190 BALLARD P, 1995, FATIGUE FRACT ENG M, V18, P397 BOWER AF, 1989, J MECH PHYS SOLIDS, V37, P471 BRAMHALL R, 1973, THESIS U OXFORD CATTANEO C, 1938, ACCADEMIA DEI LI 6 1, V27, P342 CATTANEO C, 1947, COMPRESSIONE OBLIQUA, V17, P13 CATTANEO C, 1947, RENDICONTI SEMINARIO, V17, P13 CIAVARELLA M, 1998, INT J SOLIDS STRUCT, V35, P2349 CIAVARELLA M, 1998, INT J SOLIDS STRUCT, V35, P2363 CIAVARELLA M, 1998, J APPL MECXH, V64, P998 CIAVARELLA M, 1998, P I MECH ENG C-J MEC, V212, P319 CIAVARELLA M, 1999, AM SOC TEST MATER, V1332, P696 CIAVARELLA M, 1999, ASTM STP, V1367 CIAVARELLA M, 1999, EUR J MECH A-SOLID, V18, P491 CIAVARELLA M, 1999, INT J MECH SCI, V41, P107 CIAVARELLA M, 1999, INT J MECH SCI, V41, P1533 CIAVARELLA M, 1999, INT J SOLIDS STRUCT, V36, P4149 CIAVARELLA M, 2000, P ROY SOC LOND A MAT, V456, P387 COLLA G, 1972, ASTR ASTROPHYS S, V7, P1 DAI DN, 1998, ASME, V120, P744 EDEN EM, 1911, P I MECH ENG, V875, P68 EDWARDS PR, 1981, FRETTING FATIGUE, P67 ENDO K, 1976, WEAR, V38, P311 FELLOWS LJ, 1995, WEAR, V185, P235 FELLOWS LJ, 1997, FATIGUE FRACT ENG M, V20, P61 FENNER AJ, 1956, P INT C FAT MET I ME, P368 FOUVRY S, 1998, J PHYS IV, V8, P159 GIANNAKOPOULOS AE, 1998, ACTA MATER, V46, P2955 GILLET HW, 1924, P ASTM, V24, P476 HILLS DA, 1992, ASTM STP, V1159, P69 HILLS DA, 1993, MECH ELASTIC CONTACT HILLS DA, 1994, MECH FRETTING FATIGU HILLS DA, 1996, SOLUTION CRACK PROBL HILLS DA, 1999, J STRAIN ANAL ENG, V34, P175 HOEPPNER DW, 1981, WEAR, V70, P155 HOEPPNER DW, 1994, MECH FRETTING FATIGU, P3 HUTSON AL, 1999, INT J FATIGUE, V21, P663 IYER K, 1999, IN PRESS ASME JAEGER J, 1998, ASME, V120, P677 KUNO M, 1989, FATIGUE FRACT ENG M, V12, P387 LINDLEY T, 1997, FRETTING FATIGUE S1, V19, S39 MCDOWELL JR, 1953, ASTM, V144, P24 MINDLIN RD, 1949, J APPL MECH, V16, P259 MOOBOLA R, 1998, J STRAIN ANAL ENG, V33, P17 MOOBOLA R, 1998, THESIS U OXFORD MUNISAMY RL, 1995, EUR J MECH A-SOLID, V14, P985 NEU RW, 1999, ASTM STP, V1367 NISHIOKA K, 1968, B JSME, V11, P437 NISHIOKA K, 1969, B JSME, V12, P397 NISHIOKA K, 1969, B JSME, V12, P408 NISHIOKA K, 1969, B JSME, V12, P692 NIX KJ, 1985, FATIGUE FRACT ENG M, V8, P143 NOWELL D, 1988, THESIS U OXFORD NOWELL D, 1990, WEAR, V136, P329 PAPE JA, 1999, WEAR, V229, P1205 RUIZ C, 1984, EXP MECH, V24, P208 RUIZ C, 1986, P INT C FAT SHEFF I SZOLWINSKI MP, 1996, WEAR, V198, P93 SZOLWINSKI MP, 1998, WEAR, V221, P24 TAYLOR D, 1999, INT J FATIGUE, V21, P413 THOMSON D, 1998, 3 NAT TURB ENG HIGH TOMLINSON GA, 1927, P R SOC LOND A-CONTA, V115, P472 WARLOWDAVIES EJ, 1941, P I MECH ENG, V146, P32 WATERHOUSE RB, 1981, FRETTING FATIGUE WATERHOUSE RB, 1992, INT MATER REV, V37, P77 WATERHOUSE RB, 1993, P INT C FERTT FAT SH WRIGHT T, 1972, P I MECH ENG, V186, P827 ZHOU ZR, 1999, WEAR, V229, P962 NR 69 TC 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD MAR PY 2001 VL 38 IS 10-13 BP 1791 EP 1811 PG 21 SC Mechanics GA 400QJ UT ISI:000166882800011 ER PT J AU Bartsch, M Marci, G Mull, K Sick, C TI Damage evolution in EB-PVD thermal barrier coatings for turbine blades in aircraft engines under close to reality testing conditions SO INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY LA English DT Article DE thermal barrier coating; zirconia; turbine blade; damage mechanism; lifetime prediction; thermal gradient ID LIFE AB In advanced gas turbines for aircraft engines, internally cooled turbine blades have a ceramic thermal barrier coating (TBC) to reduce the thermal load of the metallic substrate. Exhausting the full potential of the TBC to increase the turbine inlet temperature requires reliable lifetime prediction methods, since failure of the TBC will entail the immediate failure of the blade. A lifetime prediction concept for TBC's based on lifetime analyses of close to reality tests is given. Basic idea is to ensure that failure mechanisms during testing are the same as in an turbine engine. Specimens with an electron beam physical vapour deposited (EB-PVD) TBC were tested under realistic fatigue road but drastically reduced holding times. The results exhibited that the as-coated properties of the ceramic coating are sufficient to survive the required load alternations in service. The influence of kinetic damage mechanisms on the TBC-lifetime will be determined in tests with pre-aged specimens. C1 German Aerosp Ctr, DLR, Inst Mat Res, D-51147 Cologne, Germany. CR ARANA M, 1999, P TBC WINT WORKSH JA BARTSCH M, 1999, ADV ENG MATER, V1, P127 FRITSCHER K, 1999, DLR I MAT RES GOWARD GW, 1998, PROGR, V108, P73 HE MY, 1998, MAT SCI ENG A-STRUCT, V245, P168 KADEN U, 1999, ELEVATED TEMPERATURE, V3, P27 KAYASSER WA, 1999, P 7 INT C FAT 99 P R, V3, P1897 MARCI G, 2000, 3 S THERM MECH FAT B, V1371, P296 MARICOCCHI A, 1995, NASA C PUBLICATION, V3312, P79 MEIER RA, 1991, 189111 NASA UN TECHN MILLER RA, 1984, J AM CERAM SOC, V67, P517 SCHULZ U, 2000, J AM CERAM SOC, V83, P904 SCHUTZE M, 1997, PROTECTIVE OXIDE SCA WRIGHT PK, 1998, MAT SCI ENG A-STRUCT, V245, P191 NR 14 TC 1 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0268-1900 J9 INT J MATER PROD TECHNOL JI Int. J. Mater. Prod. Technol. PY 2001 VL 16 IS 1-3 BP 248 EP 257 PG 10 SC Materials Science, Multidisciplinary GA 396JF UT ISI:000166632000031 ER PT J AU Tzimas, E Mullejans, H Peteves, SD Bressers, J Stamm, W TI Failure of thermal barrier coating systems under cyclic thermomechanical loading SO ACTA MATERIALIA LA English DT Article DE coating; physical vapor deposition (PVD); plasma spray; fatigue; modeling ID GAS-TURBINE BLADES; MECHANICAL-BEHAVIOR; RESIDUAL-STRESSES; OXIDATION; FATIGUE; DEGRADATION; FILMS; LIFE; TBC AB The failure mechanisms of thermal barrier coating (TBC) systems applied on gas turbine blades and vanes are investigated using thermomechanical fatigue (TMF) tests and finite element (FE) modeling. TMF tests were performed at two levels of applied mechanical strain, namely five times and three times the critical in-service mechanical strain of an industrial gas turbine. TMF testing under the higher mechanical strain of air plasma-sprayed (APS) and electron beam-physical vapor deposition (EB-PVD) coated samples showed that both systems failed after a similar number of cycles by cracks that initiated at the bond coat/thermally grown oxide (TGO) interface and propagated through the bond coat to the substrate. When the applied mechanical strain was decreased, cracking of the bond coat in EB-PVD coated systems was suppressed, the life of the coated system increased significantly and delamination of the top-coat was observed. A subsequent FE analysis showed that, by subjecting the system to the higher mechanical strain, significant tensile stresses develop in the TGO and the bond coat that are thought to be responsible for the observed crack initiation and propagation. The FE model also predicts that cracking initiates at specific geometric features of the rough interface of a PS coated system, which was confirmed by metallographic examination of failed samples. The decrease of the applied mechanical strain and hence of the developed stresses led to the suppression of failure by bond coat cracking and activate delamination. These results outline the importance of designing TMF tests and selecting the appropriate mechanical loading in order to accelerate testing and still trigger the same failure mechanisms as observed in-service. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. AII rights reserved. C1 European Commiss, Joint Res Ctr, Inst Adv Mat, NL-1755 ZG Petten, Netherlands. Siemens AG, Power Generat Grp, KWU, Mat Technol, D-45466 Mulheim, Germany. RP Peteves, SD, European Commiss, Joint Res Ctr, Inst Adv Mat, POB 2, NL-1755 ZG Petten, Netherlands. CR *HIBB KARLSS SOR I, 1997, ABAQUS STAND US MAN, V1 *HIBB KARLSS SOR, 1998, ABAQUS VERS 5 8 BARTLETT AH, 1995, J AM CERAM SOC, V78, P1018 BAUFELD B, 1999, IAM INTERNAL REPORT BERNARD H, 1989, ADV MAT PROCESSES, V1, P529 BJERKEN C, 1998, P 15 INT THERM SPRAY, P1651 BRESSERS J, 1996, ELEVATED TEMPERATURE, V2, P275 BRESSERS J, 1996, THERMOMECHANICAL FAT, V2, P56 CHANG GC, 1987, SURF COAT TECH, V30, P13 CHANG GC, 1987, SURF COAT TECH, V32, P307 CHENG J, 1998, ACTA MATER, V46, P5839 CHRISTENSEN RJ, 1997, ACTA MATER, V45, P1761 CLYNE TW, 1996, J THERM SPRAY TECHN, V5, P401 CZECH N, 1995, MATER MANUF PROCESS, V10, P1021 DEMASIMARCIN JT, 1989, CR182230 NASA DEMASIMARCIN JT, 1990, J ENG GAS TURB POWER, V112, P521 DOLTSINIS I, 1996, STRUCT ENG MECH, V4, P679 EVANS AG, 1983, OXID MET, V20, P193 EVANS AG, 1984, INT J SOLIDS STRUCT, V20, P455 FREBORG AM, 1998, MAT SCI ENG A-STRUCT, V245, P182 FUNKE C, 1997, SURF COAT TECH, V94, P106 HAYNES JA, 1999, OXID MET, V52, P31 HE MY, 1998, MAT SCI ENG A-STRUCT, V245, P168 HSUEH CH, 1999, J AM CERAM SOC, V82, P1073 HSUEH CH, 1999, MATER SCI FORUM, V308, P442 JORDAN DW, 1993, THIN SOLID FILMS, V235, P137 JORDAN E, 1999, ATS ANN M PITTSB PA KADIOGLU Y, 1995, T ASME, V117, P94 KERKHOFF G, 1998, MAT ADV POWER ENG 19, P1669 KLOOS KH, 1994, MATERIALWISS WERKST, V25, P209 LARSSON PL, 1998, MAT SCI ENG A-STRUCT, V254, P268 LINDE L, 1995, HIGH PERFORMANCE MAT, P313 MEIER SM, 1991, CR189111 NASA MILLER TC, 1998, ENG FRACT MECH, V59, P203 MORETTO P, 1996, J MATER SCI, V31, P4817 NEWAZ GM, 1998, J ENG MATER-T ASME, V120, P149 NISSLEY DM, 1997, J THERM SPRAY TECHN, V6, P91 OSTOLAZA KM, 1996, ANAL MEC FRACT SPANI, V13, P272 PRATT, 1996, ATS RES DEV THERM BA QIAN G, 1997, ACTA MATER, V45, P1767 SERGO V, 1998, J AM CERAM SOC, V81, P3237 THURN G, 1997, MAT SCI ENG A-STRUCT, V233, P176 WRIGHT PK, 1998, MAT SCI ENG A-STRUCT, V245, P191 ZHANG YH, 1999, MATER SCI TECH SER, V15, P1031 ZOU D, 1998, NASATM1998208406REV1 NR 45 TC 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD DEC 1 PY 2000 VL 48 IS 18-19 BP 4699 EP 4707 PG 9 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 381DL UT ISI:000165747000039 ER PT J AU Gurrappa, I TI Hot corrosion of protective coatings SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Improvement in efficiencies of gas turbine engines requires a significant increase of gas inlet temperatures. This results in an increased service temperature for blade materials and consequently in enhanced oxidation and hot corrosion attack of the blade coatings, which are usually of MCrAlY type where M is Ni, Co or NiCo. This type of coating can provide protection against oxidation and hot corrosion and act as a bond coat for thermal barrier coating systems. In both cases slow growth rates and optimum adherence of the alumina scales forming on the MCrAlY coatings during high temperature exposure are significant for component life. The above mentioned properties for the alumina scales strongly depend on the coating base composition as well as on the presence of minor alloying elements. In the present paper the performance of existing superalloys during hot corrosion is briefly described followed by the results obtained on hot corrosion of MCRAlY type coatings explaining the effect of trace elements on the life of coatings in the presence of NaCl and vanadium containing environments. Optimum thickness to improve the life of superalloys with NiCoCrAlY as a bond coat and yttria stabilized zirconia thermal barrier coatings has been identified. Based on the results, an electrochemical mechanism is proposed and shows that hot corrosion of protective coatings is an electrochemical phenomenon. Hence electrochemical techniques appear to be quite useful in evaluating the coatings for hot corrosion resistance. C1 Def Met Res Lab, Hyderabad 500058, Andhra Pradesh, India. CR BEELE W, 1997, SURF COAT TECH, V94, P41 BRANDL W, 1996, SURF COAT TECH 1, V86, P41 BRINDLY WJ, 1989, ADV MATER PROCESS B, V13, P29 DESAI V, 1997, P INT C CORR CONCORR, P216 FRITSCHER K, 1995, MAT SCI ENG A-STRUCT, V190, P253 GURRAPPA I, IN PRESS OXID MET GURRAPPA I, UNPUB SURFACE COATIN GURRAPPA I, UNPUB HAMILTON JC, 1984, J AM CERAM SOC, V67, P686 HUNTZ AM, 1989, ROLE ACTIVE ELEMENTS, P81 KNIGHT R, 1998, P 15 INT THERM SPRAY, V2, P1549 LEYENS C, 1997, SURF COAT TECH, V94, P155 PINT BA, 1996, OXID MET, V45, P1 QUADAKKERS WJ, 1989, OXID MET, V32, P67 STECURA S, 1989, THIN SOLID FILMS, V182, P121 STRAWBRIDGE A, 1997, MATER SCI FORUM 1-2, V251, P365 NR 16 TC 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 2000 VL 15 IS 5 BP 761 EP 773 PG 13 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA 380WK UT ISI:000165726300010 ER PT S AU Sonoya, K Tobe, S TI Expanding of the fatigue life of thermal barrier coating by mixing MoSi2 to thermal sprayed layer SO FRACTURE AND STRENGTH OF SOLIDS, PTS 1 AND 2 SE KEY ENGINEERING MATERIALS LA English DT Article DE APS; fatigue life; MoSi2; SiO2; thermal barrier coating; VPS AB Recent trends of turbine blades of advanced aircraft gas turbine engines are to increase output power of the engines, to increase engine efficiency and to reduce environmental emission, and thus, higher operating temperatures of the engines are required. One of the technologies for increasing the operating temperature is a thermal barrier splayed coating [1.2]. The coating usually consists of a bonding coating layer of an alloy of NiCrAlY on the turbine blade and a top layer of ZrO2-Y2O3, namely; partially stabilized zirconia (PSZ). However, conventional coating systems deteriorate during turbine operation due to thermal and mechanical stresses imposed and corrosion actions by combustion gas coming from combustion chambers. Thus, the main issue is to develop measures against high oxidation rate and low fatigue life of the bonding coating layer. An idea for enhancing oxidation resistance and fatigue Life as well of thermal barrier coatings consisting of a zirconia-based coating is to provide with a self-healing capability to the coating by diffusing a suitable substance to fatigue crack surfaces formed in the coating. Excessive oxidation of the NiCrAlY layer beneath is prevented for extending fatigue life of the splayed barrier coating. Several investigations have been conducted on the matter, and a research paper [3] claims that MoSi2 in a splayed coating has a self-healing capability for cracks formed in the coating by embedding the cracks with SiO2 formed from MoSi2 at high temperatures. Thus, a new coating system containing NiCrAlY, MoSi2, and PSZ is expected to be developed instead of a two-layer coating system of NiCrAlY and PSZ. The coating system developed could be a three-layer system, or a two-layer system, one with a NiCrAlY layer and the other layer is either a gradient composition of MoSi2 and PSZ, a mixed layer of MoSi2 and PSZ, or a mixed layer of PSZ and SiO2. The other possibility is a three-layer coating with an intermediate layer of mixed powder of MoSi2 and NiCrAlY between the bonding layer and the top layer. Furthermore, a monitoring method for detecting cracking conditions in heating and cooling cycles by signals of acoustic emission is discussed. A possibility of estimating fatigue life by utilizing an X-ray method for measuring residual stress is considered as well. C1 Ishikawajima Harima Heavy Ind Co Ltd, Yokohama, Kanagawa 2358501, Japan. Ashikaga Inst Technol, Ashikaga, Tochigi 326, Japan. RP Sonoya, K, Ishikawajima Harima Heavy Ind Co Ltd, Yokohama, Kanagawa 2358501, Japan. CR FUKUMOTO M, 1993, YOSHA, V30, P163 OKAMOTO R, 1992, KAWASAKI HEAVY IND T, V112 SONOYA K, 1998, HYOMEN GIJUTU, V49, P72 ZACCHETTI N, 1992, P ITSC ORL FI US 28 NR 4 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2000 VL 183-1 BP 909 EP 914 PG 6 SC Materials Science, Ceramics; Materials Science, Composites GA BR05S UT ISI:000165527800148 ER PT J AU Kenyon, JA Cross, CJ Minkiewicz, GR TI Mechanical coupling effects on turbomachine mistuned response SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Mistuning in turbine engine bladed disks often leads to mode localization, which can result in high vibratory stresses in a single group of blades. These stresses can lower the fatigue life of the blades. Therefore, understanding mistuning is essential for design of durable rotating machinery. This investigation provides one of the first experimental demonstrations of phenomena associated with mistuning, including frequency splitting and orthogonality, Results illustrate the role of internal coupling on mistuned response. Coupling appears to be dependent on fundamental mode shape. Strong coupling prevents localization in bending modes. However, in spite of weak internal coupling, localization does not occur in an observed torsion mode. The primary consequence of mistuning is a breakdown of orthogonality between the nodal patterns of the mode shapes and harmonic excitations, resulting in numerous resonant responses to a single harmonic forcing function. The breakdown of nodal patterns also leads to increased difficulty with mode description. C1 USAF, Res Lab, Propuls Directorate, AFRL PRTE, Wright Patterson AFB, OH 45433 USA. RP Kenyon, JA, USAF, Res Lab, Propuls Directorate, AFRL PRTE, 1950 5th St,Bldg 18D, Wright Patterson AFB, OH 45433 USA. CR BENDIKSEN OO, 1986, P 27 AIAA ASME ASCE, P325 HODGES CH, 1982, J SOUND VIB, V82, P411 KENYON J, 1998, 983721 AIAA KENYON J, 1998, 983744 AIAA KENYON J, 1999, P AIAA ASME ASCE AHS, P1550 MINKIEWICZ G, 1997, 973284 AIAA SOEDEL W, 1993, VIBRATIONS SHELLS PL, P117 WEI ST, 1988, J VIB ACOUST, V110, P429 YANG MT, 1997, J ENG GAS TURB POWER, V119, P647 NR 9 TC 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD NOV-DEC PY 2000 VL 16 IS 6 BP 1149 EP 1154 PG 6 SC Engineering, Aerospace GA 374KR UT ISI:000165344800029 ER PT J AU Hocheng, H Hsu, MY TI Erosion wear of stainless steel by abrasives entrained in a water jet SO ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING LA English DT Article AB Erosion of stainless steel by abrasives entrained in a water jet often threats industrial equipment, such as the turbine blades of hydraulic power generators. It degrades system efficiency and increases maintenance costs. The current study investigates the erosion of SUS304 and SUS410 by garnet and quartz sand entrained in a water jet. The correlation between erosion time, impinging velocity, impinging angle, abrasive mass fraction, abrasive characteristics, and the material, shown as a result of the experiment, demonstrates that the erosion mechanism is ductile mode, that the material is eroded by micro-cutting, extrusion, and forging associated with severe, localized, plastic deformation. SUS410 possesses slightly better erosion resistance due to its higher yield strength. The wear fates of both materials are mainly affected by the impinging velocity and angle. The accumulative weight loss is proportional to the abrasive mass flow. The maximum wear occurs at an angle between 30 and 45 degrees. Higher velocity results in more extensive erosion wear. C1 King Fahd Univ Petr & Minerals, Dept Mech Engn, Dhahran 31261, Saudi Arabia. RP Hocheng, H, Natl Tsing Hua Univ, Dept Power Mech Engn, Hsinchu 300, Taiwan. CR BITTER JGA, 1963, WEAR, V6, P169 FINNIE I, 1960, WEAR, V3, P87 LEVY AV, 1983, WEAR, V89, P151 LEVY AV, 1986, WEAR, V108, P43 MCCABE LP, 1985, WEAR, V105, P257 MORRISON CT, 1985, WEAR, V105, P19 RUFF AW, 1979, TREATISE MATERIALS S, V16, P69 SODERBERG S, 1983, ASLE T, V26, P161 UETZ H, 1979, P DGM, P105 NR 9 TC 1 PU KING FAHD UNIV PETROLEUM MINERALS PI DHAHRAN PA C/O UNIV, DHAHRAN 31261, SAUDI ARABIA SN 0377-9211 J9 ARAB J SCI ENG JI Arab. J. Sci. Eng. PD OCT PY 2000 VL 25 IS 2B BP 187 EP 202 PG 16 SC Multidisciplinary Sciences GA 371XE UT ISI:000165203900007 ER PT J AU Viswanathan, R Bernstein, H TI Some issues in creep fatigue life prediction of fossil power plant components SO TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS LA English DT Article ID CYCLE FATIGUE; CRACK-GROWTH; TOUGHNESS; STEEL AB Creep-fatigue damage induced by thermal stresses is of major concern with respect to the integrity of many high temperature components. The concern has been exacerbated in recent years due to cyclic operation of units originally designed for base load service. Much of the past research has been aimed primarily at crack initiation phenomena and, although useful from a design point of view, it is not always relevant to plant operators who in many instances can run components containing tolerable cracks. In terms of both crack initiation and crack growth prediction, variation in material, temperature environment, stress state, etc. have made it impossible to apply a single damage rule for all cases. The need for component-specific life prediction using appropriate material property data generated under conditions relevant to the service and using the proper failure criterion, has become very apparent. In the face of this need, thermomechanical fatigue (TMF) testing, creep-fatigue crack growth testing and bench marking against field experience is essential. This paper will assess the current state of the art with respect to creep-fatigue life prediction especially with a view to provide a plant user's perspective to the research community and to present a case study an TMF life prediction of combustion turbine blades. C1 Elect Power Res Inst, Palo Alto, CA 94303 USA. SW Res Inst, San Antonio, TX 78238 USA. RP Viswanathan, R, Elect Power Res Inst, 3412 Hillview Ave, Palo Alto, CA 94303 USA. CR 1991, BOILER LIFE EVALUATI, V4 BERNSTEIN HL, 1993, ASTM STP, V1186, P212 BICEGO V, 1982, PVP, V60 BORDEN MP, 1987, CS54588 EL POW RES I, V5 CINCOTTA G, 1988, GAS TURBINE LIFE MAN COFFIN LF, 1969, P 2 INT C FRACT BRIG, P643 FOULDS J, 1994, J ENG MATER-T ASME, V116, P457 GELL M, 1973, ASTM SPEC TECH PUBL, V520, P37 GOTO T, 1994, TR103619 EL POW RES, V4 HAIGH JR, 1976, MATER SCI ENG, V26, P167 HARROD DL, 1976, ASME MPC S CREEP FAT, P87 KADOYA A, 1985, LIFE ASSESSMENT IMPR KIMURA K, 1988, HIGH TEMPERATURE CRE, P247 KUWABARA K, 1985, ADV LIFE PREDICTION, P131 MAJUMDAR S, 1976, ASME MPC S CREEP FAT, P323 MANSON SS, 1973, ASTM STP, V520, P744 MILLER DA, 1984, HIGH TEMPERATURE MAT, V6, P115 OSTERGREN WJ, 1976, J TEST EVAL, V4, P327 PRIEST RH, 1983, ASME C ALB, P115 SAXENA A, 1981, ASTM STP, V743, P86 SCARLIN RB, 1977, P 4 INT C FRACT ICF4, V2, P849 SOLOMON HD, 1973, ASTM STP, V520, P112 TAIRA S, 1962, CREEP STRUCTURES, P96 THOMAS G, 1980, INT C ENG ASP CREEP, P167 TIMO DP, 1984, TUR SEM SCHEN VISWANATHAN R, 1989, DAMAGE MECH LIFE ASS VISWANATHAN R, 1991, J ENG MATER-T ASME, V113, P263 YAMAGUCHI K, 1986, INT C CREEP TOK APR, P47 YOON KB, 1993, INT J FRACTURE, V59, P95 NR 29 TC 0 PU INDIAN INST METALS PI CALCUTTA PA METAL HOUSE, PLOT 13/4, BLOCK AQ, SECTOR V, SALT LAKE, CALCUTTA 700 091, INDIA SN 0019-493X J9 TRANS INDIAN INST MET JI Trans. Indian Inst. Met. PD JUN PY 2000 VL 53 IS 3 SI Sp. Iss. SI BP 185 EP 202 PG 18 SC Metallurgy & Metallurgical Engineering GA 366MA UT ISI:000090008100010 ER PT J AU Tsao, TP Lin, CH TI Long term effect of power system unbalance on the corrosion fatigue life expenditure of low pressure turbine blades SO IEE PROCEEDINGS-SCIENCE MEASUREMENT AND TECHNOLOGY LA English DT Article ID GENERATOR SHAFTS AB Usually, the effect of pourer system unbalance is based on the limitation of generator thermo-rating. According to this limitation the protection scheme for system unbalance is designed. However, the authors fmd that the long-term effects of power system unbalance may become a cause of fatigue damage on low-pressure (LP) turbine blades even though the system unbalance is still within the limitation of generator thermal rating. As a result, turbine blades are possibly unprotected by traditional system unbalance protection schemes. In particular, for the last three stages of blades that are made of AISI-403 material and with vibration modes closing to the double-frequency avoidance zone, the long-term cumulative corrosion fatigue life expenditure of blades may be relatively large due to the inevitable corrosive operating environment with NaCl. Therefore, the influence of power system unbalance on turbine blades might be essential and would not always be neglected. C1 Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. RP Tsao, TP, Natl Sun Yat Sen Univ, Dept Elect Engn, Kaohsiung 80424, Taiwan. CR *MIT HEAV IND LTD, 1996, INV RES BLAD FAIL L BATES RC, 1984, CS2932 EPRI CONN AF, 1973, P ASTM STP, V520, P273 CUDWORTH CJ, 1990, IEE PROC-C, V137, P327 DEWEY RP, 1985, CS3891 EPRI FARIED SO, 1996, IEE P-GENER TRANSM D, V143, P487 GONZALEZ AJ, 1984, IEEE T POWER AP SYST, V103, P3218 HAMMONS TJ, 1980, IEEE T PAS, V99, P1652 JONAS O, 1981, P EPRI WORKSH CORR F LINDSEY WT, 1979, POWER ENG, V83, P68 MASRUR MA, 1991, IEE PROC-C, V138, P47 SMITH SH, 1983, ASTM STP, V791, P120 STELTZ WG, 1981, ASME WINT ANN M NOV WALKER K, 1970, P ASTM STP, V462, P234 WILLERTZ LE, 1981, EPRI WORKSH CORR FAT WILLIAMS RA, 1986, IEEE T ENERGY CONVER, V1, P80 NR 16 TC 5 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1350-2344 J9 IEE PROC-SCI MEAS TECHNOL JI IEE Proc.-Sci. Meas. Technol. PD SEP PY 2000 VL 147 IS 5 BP 229 EP 236 PG 8 SC Engineering, Electrical & Electronic GA 361HE UT ISI:000089717000003 ER PT J AU Builo, SI Bezhenov, SA TI Investigation of acoustic emission due to deformation of titanium alloy and some results of acoustic-emission diagnostics of its predestruction states SO RUSSIAN JOURNAL OF NONDESTRUCTIVE TESTING LA English DT Article AB The paper presents acoustic-emission (AE) characteristics of the Ti-Al-Mo-Si alloy. The energy of one AE event has been estimated over the entire frequency band under investigation. An S-shaped curve of the logarithm of the frequency of AE events plotted against the strain has been obtained, and the physical interpretation of such a dependence has been given. A tentative explanation of the delay of AE events on the initial stage of the material deformation with a stress concentrator has been suggested. On the base of the correlation between the service-life expectancy and the frequency of AE events, which has been established in our experiments, the degree of confidence in the diagnostic data concerning the predestruction state of gas-turbine blades in turbojet aircraft engines has been estimated. C1 Rostov State Univ, Res Inst Mech & Appl Math, Rostov On Don 344006, Russia. Russia Zaporozhye State Tech Univ, Zaporozhe, Ukraine. RP Builo, SI, Rostov State Univ, Res Inst Mech & Appl Math, Rostov On Don 344006, Russia. CR ANDREIKIV AE, 1989, METOD AKUSTICHESKOI BEZHENOV AI, 1999, PROBL PROCHN, P139 BEZHENOV SA, 1997, T 8 NAUCHN K ZAP, P95 BEZHENOV SA, 1998, NOVI KONSTRUKTZIINI, P48 BUILO SI, 1989, ACOUSTIC EMISSION 1, P125 BUILO SI, 1989, TEKHNICHESKAYA DIAGN, P15 BUILO SI, 1995, DEFEKTOSKOPIYA, P14 BUILO SI, 1996, DEFEKTOSKOPIYA, P20 BUILO SI, 1996, TEKHN DIAGNOSTIKA I, P40 BUILO SI, 1997, DEFEKTOSKOPIYA, P84 BUNINA NA, 1990, ISSLEDOVANIE PLASTIC GRESHNIKOV VA, 1976, AKUSTICHESKAYA EMISS IVANOV VI, 1981, AKUSTIKOEMISSIONNYI TRIPALIN AS, 1986, FIZIKOMEKHANICHESKIE TROITSKII VA, 1987, SPRAVOCHNIK OBORUDOV TRUFYAKOV VI, 1990, PROCHNOST SVARNYKH S NR 16 TC 1 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1061-8309 J9 RUSS J NONDESTRUCT T-ENGL TR JI Russ. J. Nondestr. Test. PD MAY PY 2000 VL 36 IS 5 BP 307 EP 314 PG 8 SC Materials Science, Characterization & Testing GA 357DE UT ISI:000089482600001 ER PT S AU Sequeira, AD Moretto, P Bressers, J TI Residual stress and microstructure of CoNiCrAlY coated superalloys upon thermo-mechanical fatigue SO EUROPEAN POWDER DIFFRACTION, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article DE residual stress; CoNiCrAlY coatings; superalloys; thermomechanical fatigue; X-ray diffraction; scanning and transmission electron microscopy AB It has been observed that under certain thermo-mechanical fatigue (TMF) conditions overlay coatings have a detrimental influence on the life of superalloys when compared with the uncoated material. The different thermal expansion coefficients of the coating and substrate induce residual stresses at the interface region between them. These stresses clearly influence the TMF behaviour of the material and are the main concern in this communication. The thermo-mechanical fatigue cycles, experienced at various parts of a turbine blade in service, have been reproduced in the laboratory. Residual stress measurements were performed on several coated and uncoated samples. The stresses were determined using the Sin(2) Psi method under a biaxial approximation, for both gamma and beta-phases throughout the TMF tests. SEM and TEM were used to monitor changes in the microstructure on both the coating and the substrate material. Throughout the test an oxide layer (Al2O3) was formed and grew at the surface producing a depletion of the Al rich phase beta-NiAl in the matrix. The main mechanisms of damage were observed to be creep at high temperature and cracking at low temperature. C1 Nucl & Technol Inst, Dept Phys, PO-2685 Sacavem, Portugal. Inst Adv Mat, NL-1755 ZG Petten, Netherlands. RP Sequeira, AD, Nucl & Technol Inst, Dept Phys, Estrada Nacl 10, PO-2685 Sacavem, Portugal. CR BRESSERS J, 1995, ASTM STP, V1263, P56 BRESSERS J, 1996, ELEVATED TEMPERATURE, V2, P275 SEQUEIRA AD, 1998, EUROMAT 98 MAT OCEAN, V1, P121 NR 3 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 321-3 PN Part 1&2 BP 748 EP 753 PG 6 SC Materials Science, Multidisciplinary GA BQ57X UT ISI:000088849300125 ER PT J AU Coutant, CC Whitney, RR TI Fish behavior in relation to passage through hydropower turbines: A review SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Review ID ATLANTIC SALMON SMOLTS; COLUMBIA RIVER; SALAR L; MIGRATION; ANIMALS; SYSTEM; SIZE; DAM AB We evaluated the literature on fish behavior as it relates to passage of fish near or through hydropower turbines. Our goal was to foster compatibility of engineered systems with the normal behavior patterns of fish species and life stages such that passage into turbines and injury in passage are minimized. In particular, we focused on aspects of fish behavior that could be used for computational fluid dynamics (CFD) modeling of fish trajectories through turbine systems. Salmon smolts approaching dams are generally surface oriented and follow flow. They can be diverted from turbines by spills or bypasses, with varying degrees of effectiveness. Smolts typically become disoriented in dam forebays. Those smolts drawn into turbine intakes orient vertically to the ceilings bur are horizontally distributed more evenly, except as they are affected by intake-specific turbulence and vortices. Smolts often enter intakes while oriented with their heads upstream, but they may change orientation in the flow fields of the intake. Nonsalmonids most often enter intakes from the vicinities of shorelines, and they do so episodically, which suggests accidental capture of schools (often of juveniles or in cold water) and little behavioral control during turbine passage. Models of fish trajectories should not assume neutral buoyancy throughout the time period during which a fish passes through a turbine, largely because of pressure effects on swim bladders and the resulting compensatory behavior. Fish use their lateral line system to sense obstacles and to change their orientation, but this sensory-response system may not be effective in the rapid passage times and complex pressure regimes of turbine systems. The effects of preexisting stress levels on fish performance in turbine passage (especially as they affect trajectories) are not known but may be important. There are practical limits of observation and measurement of fish and hows in the proximity of turbines that may inhibit the development of much information that is germane to developing a more fish-friendly turbine. We provide recommendations for CFD modelers of fish passage and for additional research. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Coutant, CC, Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. CR *BIOS INC, 1983, HYDR ASS DOWNSTR MIG *BIOS INC, 1984, HYDR ASS DOWNSTR MIG *EPRI, 1986, 26941 EPRI *EPRI, 1998, TR109483 *EPRI, 1998, TR111517 *FERC, 1988, HYDR DEV UPP OH RIV *FERC, 1995, DPR10 FERC *FPC, 1994, DOEBP389063 *HARZ ENG CO, 1993, RESP JUV CLUP LOUV H *NMFS, 1995, PROP REC PLAN SNAK R *NORM ASS, 1986, AN FISH MOV VIC LOCK *NPPC, 1994, COL RIV BAS FISH WIL *NRC, 1996, UPSTR SALM SOC PAC N *OTA, 1995, OTAENV641 *RMC, 1994, SURV YEARL FALL CHIN *RMC, 1995, SURV YEARL FALL CHIN *USACE, 1995, P 1995 TURB PASS SUR *USFWS, 1992, JOINT AG FISH ENTR T, V2 *WAPORA, 1987, FISH PASS STUD RAC N ACHORD S, 1995, DOEBP188002, V5 ADAMS SM, 1990, AM FISHERIES SOC S B, V8 ALEXANDER RM, 1965, J EXP BIOL, V43, P131 ALEXANDER RM, 1990, AM ZOOL, V30, P189 ALEXANDER RM, 1993, PHYSL FISHES, P75 ARNOLD GP, 1974, BIOL REV, V49, P515 BELL MC, 1981, UPDATED COMPENDIUM S BERGGREN TJ, 1993, N AM J FISH MANAGE, V13, P48 BLECKMANN H, 1986, BEHAV TELEOST FISHES, P177 BOUCK GR, 1980, T AM FISH SOC, V109, P703 BRETT JR, 1953, J FISH RES BOARD CAN, V10, P548 BROOKSHIER PA, 1995, P INT C HYDR AM SOC, P2003 BUETTNER EW, 1995, DOEBP1163110 CADA GF, 1994, REV INFORMATION PERT CADA GF, 1997, DOEID10578 CHAUDHRY MH, 1993, OPEN CHANNEL FLOW CLAY CH, 1994, DESIGN FISHWAYS OTHE COLLINS GB, 1964, SUMMARY PROGR FISH P COUTANT CC, 1998, ORNLTM13608 CRAMER FK, 1960, 2 US ARM CORPS ENG CRAMER FK, 1961, 4 US ARM CORPS ENG CRAMER FK, 1965, FISH PASSAGE HYDRAUL DADSWELL MJ, 1986, FISHERIES, V11, P26 DADSWELL MJ, 1994, BIOL J LINN SOC, V51, P93 DUNN CA, 1978, EVALUATION DOWNSTREA EBEL WJ, 1981, 50 YEARS COOPERATION, P147 EICHER GE, 1988, FISH PROTECTION STRE, P1 FANGSTAM H, 1993, J FISH BIOL, V43, P517 FISHER RK, 1997, HYDRO REV, V16, P20 FRANCFORT JE, 1994, DOEID10360 FRIED SM, 1978, J FISH RES BOARD CAN, V35, P76 GESSEL MH, 1991, N AM J FISH MANAGE, V11, P400 GESSEL MH, 1995, STUDIES EVALUATE EFF GIORGI AE, 1986, DOEBP396441 GIORGI AE, 1988, DOEBP212372 GIORGI AE, 1988, N AM J FISH MANAGE, V8, P25 GIORGI AE, 1995, REV BIOL INVESTIGATI GROOT C, 1965, BEHAVIOUR S, V14, P1 GROOT C, 1982, P SALM TROUT MIGR BE, P1 GROVES AB, 1972, EFFECTS HYDRAULIC SH HARO A, 1998, T AM FISH SOC, V127, P118 HARVEY HH, 1963, THESIS U BRIT COLUMB HOAR WS, 1954, J FISH RES BOARD CAN, V11, P69 HOLLAND L, 1984, ANAL EXISTING INFORM JOHNSON GE, 1992, FISH RES, V14, P221 JOHNSON GE, 1997, CRITICAL ASSESSMENT JOHNSON L, 1987, HYDROACOUSTIC EVALUA JOHNSON RL, 1999, PNWD2448 JONES FRH, 1951, J EXP BIOL, V28, P553 JONES FRH, 1952, J EXP BIOL, V29, P94 KALMIJN AJ, 1989, MECHANOSENSORY LATER, P187 KUEHL S, 1986, HYDROACOUSTIC EVALUA LONG CW, 1968, US FISH WILDLIFE SER, V66, P599 LONG CW, 1970, FURTHER RES FINGERLI LUCAS CW, 1981, CAVITATION HYDRAULIC, P307 LUPANDIN AI, 1996, J ICHTHYOLOGY, V36, P408 MAGNE RA, 1987, HYDROACOUSTIC MONITO MAGNUSON JJ, 1970, COPEIA, P56 MAGNUSON JJ, 1978, FISH PHYSIOL, V7, P239 MATHUR D, 1996, CAN J FISH AQUAT SCI, V53, P542 MCCLEAVE JD, 1978, J FISH BIOL, V12, P559 MCCOMAS RL, 1994, STUDIES EVALUATE EFF MCDONALD J, 1960, J FISH RES BOARD CAN, V17, P655 MCFADDEN BD, 1990, HYDROACOUSTIC EVALUA MCFADDEN BD, 1992, HYDROACOUSTIC EVALUA MCLEAN RB, 1980, ORNLNUREGTM340 MIGHETTO L, 1994, SAVING SALMON HIST U MONTEN E, 1985, FISH TURBINES MUKAI T, 1996, ICES J MAR SCI, V53, P245 NEITZEL D, 1999, HYDRO REV, V18, P82 NELSON WR, 1994, DOEBP217082, P39 NESTLER JM, 1995, EL9513 USA CORPS ENG NESTLER JM, 1995, IMAGING SMOLT BEHAV NORTHCOTE TG, 1962, J FISH RES BOARD CAN, V19, P201 ODEH M, 1999, INNOVATIONS FISH PAS ODGAARD AJ, 1990, J HYDRAUL ENG-ASCE, V116, P1301 OLSON FW, 1987, FISH POPULATION ENTR OLSON FW, 1988, FISHERIES RESOURCE S, V2 OULLETTE DA, 1988, HYDR EV JUV FISH PAS PAVLOV DS, 1994, DOKL AKAD NAUK, V336, P215 PAVLOV DS, 1999, DOWNSTREAM MIGRATION PLOSKEY GR, IN PRESS EFFECTIVENE POPPER AN, 1993, PHYSL FISHES, P99 POPPER AN, 1998, T AM FISH SOC, V127, P673 PRENTICE EF, 1990, FISH MARKING TECHNIQ, P323 RAEMHILD GA, 1985, P S SMALL HYDR FISH, P244 RANSOM BH, 1988, FISH PROTECTION STEA, P1 RANSOM BH, 1990, HYDROACOUSTIC EVALUA RAYMOND HL, 1980, ASSESSMENT SMOLT MIG RIEMAN BE, 1991, T AM FISH SOC, V120, P448 RUTTER C, 1902, B BUREAU FISHERIES, V22, P65 SCHOENEMAN DE, 1961, T AM FISH SOC, V90, P58 SCHRECK CB, 1990, BIOL INDICATORS STRE, P29 SCHRECK CB, 1995, DOEBP928185 SHEER MB, 1997, MOVEMENT BEHAV RADIO SHTAF LG, 1983, J ICHTHYOLOGY, V23, P129 SINHA SK, 1998, J HYDRAUL ENG-ASCE, V124, P13 SINHA SK, 1999, HYDRO REV, V18, P50 SKALSKI J, CANADIAN J FISHERIES SKOROBOGATOV MA, 1993, HYDRAULIC BIOL RES F, P67 SKOROBOGATOV MA, 1996, J ICHTHYOLOGY, V36, P654 SMITH LS, 1982, AQUACULTURE, V28, P153 SNELLING JC, 1994, 82003 BONN POW ADM THORPE JE, 1978, J FISH BIOL, V12, P541 THORPE JE, 1981, J FISH BIOL, V19, P519 THORPE JE, 1982, MECH MIGRATION FISHE, P387 TURBAK SC, 1981, ORNLTM7521 TURNER AR, 1993, P S FISH PASS TECHN, P123 TURNPENNY AWH, 1992, EXPT STUDIES RELATIN VENDITTI DA, 1997, IDENTIFICATION SPAWN, P48 WAGNER E, 1973, EVALUATION FISH FACI WEITKAMP DE, 1980, T AM FISH SOC, V109, P659 WHITNEY RR, 1997, 9715 NPPC WILLIAMS R, IN PRESS RETURN RIVE WILLIS CF, 1981, 81ABC00173 NATL MAR WILLIS CF, 1982, DACW5778C0056 USA CO WINCHELL FC, 1991, GSEN7036 EPRI NR 136 TC 36 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 TRANS AMER FISH SOC JI Trans. Am. Fish. Soc. PD MAR PY 2000 VL 129 IS 2 BP 351 EP 380 PG 30 SC Fisheries GA 342GB UT ISI:000088635900003 ER PT J AU Bruna, AA Alba, JA Villanueva, FJGD Gonzalez, PV TI Protective coatings for aeronautic and power generation turbines components deposited by plasma spray SO BOLETIN DE LA SOCIEDAD ESPANOLA DE CERAMICA Y VIDRIO LA Spanish DT Article DE coatings; plasma spray; corrosion; oxidation; high temperature; aluminide; chrome-aluminide ID ALUMINIDE COATINGS; SUPERALLOYS AB Coatings produced by aluminium diffusion, called aluminide are employed to increase the oxidation and corrosion resistance, increasing the life of Ni and Co base superalloys components at temperatures comprised between 900 and 1050 degrees C. Consequently these coatings are frequently employed in aeronautic and Fewer generation turbines as well as in the chemical industry. Aluminides are industrially produced by pack cementation or CVD and recently it has been demonstrated that its resistance significantly increases when Cr is added (chrome-aluminides). During this work, a feasibility study has been carried out in order to determine if plasma spray can be employed for depositing this type of coatings on turbine blades. Therefore, aluminium and aluminium/chromium layers were deposited on Ni base IN100 superalloy specimens that were subsequently subjected to a diffusion heat treatment under Ar flow Characterisation and analysis of the coatings were carried out by metallography, SEM and EDS. Cyclic oxidation tests were carried out at 1050 degrees C while molten sulphate hot corrosion was performed at 900 degrees C. The results of this preliminary study are promising and indicate that plasma spray can be developed as an industrial process for production of aluminide and chrome-aluminide coatings. CR BIANCO R, 1993, J ELECTROCHEM SOC, V140, P1181 FITZER E, 1978, MAT COATINGS RESIST, P253 GOWARD GW, 1971, OXID MET, V3, P475 GOWARD GW, 1998, SURF COAT TECH, V108, P73 LINDBLAD NR, 1969, OXID MET, V1, P143 NEJEDLIK JF, 1970, AFMLTR70208 STRINGER, 1998, SURF COAT TECHNOL, V108, P1 WARNES BM, 1997, SURF COAT TECH, V94, P1 NR 8 TC 0 PU SOCIEDAD ESPANOLA CERAMICA VIDRIO PI MADRID PA ANTIGUA CTRA MADRID-VALENCIA, KM 24,300, ARGANDA DEL REY, 28500 MADRID, SPAIN SN 0366-3175 J9 BOL SOC ESP CERAM VIDR JI Bol. Soc. Esp. Ceram. Vidr. PD JUL-AUG PY 2000 VL 39 IS 4 BP 540 EP 547 PG 8 SC Materials Science, Ceramics GA 340PJ UT ISI:000088543200030 ER PT J AU Komazaki, S Shoji, T Sato, M TI Creep life prediction of Ni-base superalloy used in advanced gas turbine blades by electrochemical method SO JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING LA English DT Article DE nondestructive inspection; electrochemistry; creep; life prediction; Ni-base superalloy; gamma/gamma ' interface; electrochemical technique AB In order to develop a methodology for creep life assessment of directionally solidified Ni-base superalloy CM247LC, commonly used in advanced bras turbine blades, changes in electrochemical property of the alloy caused bq creep have been investigated. Experimental results on electrochemical polarization measurements revealed that the peak current densities "I-p" and "I-pr", which appeared at a specific potential during potentiodynamic polarization reactivation measurements in a dilute glyceregia solution, increased linearly with the life fraction at an early stage of creep life and were uniquely correlated with a newly proposed Arrhenius-type parameter ''(t/t(r))exp(-Q(c)/RT)". The creep life fraction can be nondestructively evaluated by electrochemical polarization measurements and the above parameter. C1 Akita Prefectural Univ, Dept Machine Intelligence & Syst Engn, Akita 0150055, Japan. Tohoku Univ, Fracture Res Inst, Grad Sch Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. Tojoku Elect Power Co Inc, New York Off, New York, NY 10022 USA. RP Komazaki, S, Akita Prefectural Univ, Dept Machine Intelligence & Syst Engn, 84-4 Tsuchiya Ebinokuchi, Akita 0150055, Japan. CR *JAP I MET, 1993, MET DAT BOOK, P23 HOPGOOD AA, 1986, MATER SCI ENG, V82, P27 HOPGOOD AA, 1988, MATER SCI TECHNOL, V4, P146 KOMAZAKI S, 1998, T JPN SOC MECH ENG, V64, P1997 KOMAZAKI S, 1998, THESIS TOHOKU U KOWAKA M, 1983, CORROSION DAMAGE COR, P22 SCHMIDT R, 1992, METALL TRANS A, V23, P745 SCHMIDT R, 1992, SCRIPTA METALL MATER, V26, P1919 WATANABE Y, 1995, P 1995 ASME JSME PRE, V315, P397 NR 9 TC 1 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160-0016, JAPAN SN 1344-7912 J9 JSME INT J A-SOLID MECH MAT E JI JSME Int. J. Ser. A-Solid Mech. Mat. Eng. PD APR PY 2000 VL 43 IS 2 BP 156 EP 165 PG 10 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 332VT UT ISI:000088095200007 ER PT J AU Lenets, YN Bellows, RS TI Crack propagation life prediction for Ti-6Al-4V based on striation spacing measurements SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE high cycle fatigue (HCF); fractography; fatigue striations; fatigue life; crack initiation; crack propagation; titanium alloy Ti-6Al-4V AB A combined experimental and numerical study was conducted on forged Ti-6A1-4V titanium alloy representative of a turbine engine fan blade material. The experimental information on striation spacing in the given material was converted into da/dN-Delta K data and further extrapolated towards lower crack growth rates assuming a linear relationship between da/dN and Delta K when plotted in log-log coordinates. The NASA Crack Analysis Code was used with several different sets of the crack growth rate input to predict the number of load cycles required to propagate a semi-circular surface crack from a certain initial size to final fracture in a round bar of nominal diameter 5 mm. For an initial flaw size of 10 to 50 mu m, predictions based on the da/dN-Delta K test results from both compact tension and surface flaw specimens greatly overestimated the fatigue crack propagation life. On the contrary, very good agreement with available experimental data has been shown to exist for predictions based on extrapolated striation spacing measurements. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Allied Signal Aerosp Co, Phoenix, AZ 85072 USA. RP Lenets, YN, Allied Signal Aerosp Co, POB 52181, Phoenix, AZ 85072 USA. CR BELLOWS RS, 1998, MECH BEHAV ADV MAT, V84, P27 BOTVINA LR, 1985, SOV MATER SCI, V21, P144 CHEN EY, 1995, METALL MATER TRANS A, V26, P3163 ELBER W, 1971, ASTM STP, V486, P230 EYLON D, 1998, SUMMARY AVAILABLE IN FORMAN RG, 1986, ASTM STP, V905, P59 HERTZBERG R, 1979, INT J FRACTURE, V15, R69 MILLER GA, 1969, T Q ASM, V3, P651 NR 8 TC 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD JUL PY 2000 VL 22 IS 6 BP 521 EP 529 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 326VP UT ISI:000087757900007 ER PT J AU Aizawa, K Tomimitsu, H Tamaki, H Yoshinari, A TI Morphology of Ni-base superalloys via very small-angle neutron scattering technique SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SINGLE-CRYSTAL; STRESS; ALLOYS AB Very small-angle neutron scattering (VSANS) was used to develop a nondestructive inspecting technique for predicting the residual life time of turbine blades made from single crystal Ni-base superalloy. The VSANS curves, obtained from single crystalline CMSX-4 samples with the various degrees of damage, clearly show the first order peak of the lamellar structure created by a sequence of gamma and gamma' phases in this material. The peak shifts in the direction of lower scattering vector magnitudes when the creep damage increases, which reflects a corresponding increase of the period of the lamellar structure. According to the VSANS data, the interphase distance in the samples increases gradually (but does not grow rapidly) with increasing creep damage when the latter is < 54% of the creep leading to rupture. Thus, the interphase distance is a sensitive parameter which can be used to describe the morphological changes in Ni-base superalloys related to creep damage. The results are consistent with those obtained from scanning electron microscopy. C1 Japan Atom Energy Res Inst, Adv Sci Res Ctr, Tokai, Ibaraki 31911, Japan. Hitachi Ltd, Hitachi Res Lab, Hitachi, Ibaraki, Japan. RP Aizawa, K, Japan Atom Energy Res Inst, Adv Sci Res Ctr, 2-4 Shirakata Shirane, Tokai, Ibaraki 31911, Japan. CR AIZAWA K, 1995, PHYSICA B, V213, P884 BELLET D, 1992, J PHYS I, V2, P1097 BIANCHI P, 1988, MATER SCI FORUM, V27, P429 FAHRMANN M, 1995, ACTA METALL MATER, V43, P1007 FULLAGAR KPL, 1996, ASME, V188, P380 GIAMEI AF, 1985, SOC S P, V39, P293 MILLER RJR, 1978, J APPL CRYSTALLOGR, V11, P583 SEQUEIRA AD, 1997, J APPL CRYSTALLOGR 5, V30, P575 STRUNZ P, 1994, ACTA PHYS HUNG, V75, P279 STRUNZ P, 1997, J APPL CRYSTALLOGR 5, V30, P597 TAKAHASHI T, 1981, JPN J APPL PHYS, V20, L837 TAKAHASHI T, 1983, PHYSICA B & C, V120, P362 TOMIMITSU H, 1986, J NON-CRYST SOLIDS, V88, P388 TOMIMITSU H, 1995, PHYSICA B, V213, P818 NR 14 TC 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYST JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 PN Part 3 BP 847 EP 850 PG 4 SC Crystallography GA 317VX UT ISI:000087248600102 ER PT J AU Cailletaud, G Caruel, F Gallerneau, F Mounoury, V Pallot, P TI Life prediction and sizing of turbine blades SO JOURNAL DE PHYSIQUE IV LA French DT Article C1 Ecole Mines, Ctr Mat, URA 866 CNRS, F-91003 Evry, France. SNECMA YLE, F-77550 Moissy Cramayel, France. Off Natl Etud & Rech Aerosp, ORce, F-92322 Chatillon, France. RP Cailletaud, G, Ecole Mines, Ctr Mat, URA 866 CNRS, BP 87, F-91003 Evry, France. CR BESSON J, 1998, OBJECT ORIENTED PROG, P567 CHABOCHE JL, 1989, INT J PLASTICITY, V5, P247 FAHRAT C, 1994, IMPLICIT PARALLEL PR, V2 FEYEL F, 1997, C NAT CALC STRUCT GALLERNEAU F, 1995, THESIS LEMAITRE J, 1985, ETUDE MODELISATION E MERIC L, 1991, J ENG MATER-T ASME, V113, P162 NR 7 TC 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD MAR PY 2000 VL 10 IS P4 BP 181 EP 186 PG 6 SC Physics, Multidisciplinary GA 302QP UT ISI:000086376900026 ER PT J AU Muljadi, E Pierce, K Migliore, P TI Soft-stall control for variable-speed stall-regulated wind turbines SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article DE renewable energy; wind turbine; stall control; variable speed; fatigue load mitigation; wound rotor induction generator AB A variable-speed, fixed-pitch wind turbine control strategy was investigated to evaluate the feasibility of constraining rotor speed and power output without the benefit of active aerodynamic control devices. A strategy was postulated to control rotational speed by specifying the demanded generator torque. By controlling rotor speed in relation to wind speed, the aerodynamic power extracted by the blades from the wind was manipulated. Specifically, the blades were caused to stall in high winds. In low and moderate winds, the demanded generator torque and the resulting rotor speed were controlled and the wind turbine operated near maximum efficiency. Turbine models were developed and simulations of operation in turbulent winds were conducted. Results indicated that rotor speed and power output were well regulated. Preliminary investigations of system dynamics (E. Muljadi, K. Pierce, P. Migliore, A conservative control strategy for variable-speed stall-regulated wind turbines, AIAA-2000-31 A Collection of the 2000 ASME Wind Energy Symposium Technical Papers presented at the 38th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 2000). Showed that, compared to fixed-speed operation, variable-speed operation caused cyclic loading amplitude to be reduced for the turbine blades and low-speed shaft and slightly increased for the tower loads. This result suggests that implementation of the proposed control strategy will have a favorable impact on the turbine's fatigue life. The concept was implemented on a 275 kW wind turbine test bed (K. Pierce, P. Migliore, Maximizing the energy capture of fixed-pitch variable-speed wind turbines, AIAA-2000-0032 ASME Wind Energy Symposium Technical Papers presented at the 38th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 2000). Test data show that the wind turbine performance matches the predicted simulation results. The control concept was shown to operate the wind turbine near maximum efficiency in low-to-moderate wind speeds, while stalling the rotor in the high winds to regulate speed and output power. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Wind Technol Ctr, Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Muljadi, E, Natl Wind Technol Ctr, Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. CR CONNOR B, 1993, 1993 WIND EN CONV 19 FARDOUN AA, 1993, P WINDP 93 SAN FRANC, P134 HANSEN AC, 1996, USERS GUIDE WIND TUR KELLEY ND, 1993, 12 ASME WIND EN S HO MULJADI E, 1996, ASME WIND EN S 1996 MULJADI E, 1998, AM CONTR C 1998 PHIL WRIGHT A, 1994, WINDP 94 MINN MN MAY NR 7 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AERODYN JI J. Wind Eng. Ind. Aerodyn. PD APR 24 PY 2000 VL 85 IS 3 BP 277 EP 291 PG 15 SC Engineering, Civil; Mechanics GA 308FX UT ISI:000086700800005 ER PT J AU Kachi, T Yamamoto, T Furuhata, T Arai, N TI Views on the future of gas turbine system as energy conversion technology SO KAGAKU KOGAKU RONBUNSHU LA Japanese DT Article DE energy conversion; gas turbine; high efficiency; cogeneration system; materials technology ID C/C COMPOSITES; METHANE-AIR; COMBUSTION AB Energy is the basis of industrial civilization. Without it, modern life would cease to exist. The important point is that limited fossil fuels are converted into energy in a mure efficient way. One of the most effective conversion systems is a gas turbine, which is a major power source used in the generation of electricity. A gas turbine is comprised of three main sections a compressor, a combustor, and a power turbine. Compressed air and fuel are burned in a combustor, and the resulting hot Ras is allowed tu expand through a turbine to perform work. Thermal efficiency of the gas turbine increases with the rise of Turbine Inlet Temperature (TIT). TIT is, however, limited with the heat-resisting temperature of the first stage nozzle and turbine blades. This physical limit is always climbing with the advances in materials technology. System design including gas turbine has also been developed vigorously. Cogeneration is the system that supplies not only electric power but also steam or hot water. The application of this system has been popularized for both society and industry. As a present trend, a new concept system that was named "Chemical aas turbine system" and the latest actual machine ''501 G" are introduced. C1 Nagoya Univ, Res Ctr Adv Energy Convers, Nagoya, Aichi 4648603, Japan. RP Kachi, T, Nagoya Univ, Res Ctr Adv Energy Convers, Nagoya, Aichi 4648603, Japan. CR *FED EL POW CO, 1998, EL REV JAP, P8 *NTS, 1998, KANK SYOUEN NOT EN S, P936 *ZAIR JOUH CTR, 1988, SIN ZAIRY SEIK KAK Z AKITA E, 1999, J GAS TURBINE SOC JA, V27, P138 ANAND AK, 1996, J ENG GAS TURB POWER, V118, P732 ARAI N, 1997, P ASME INT JOINT POW, V1, P423 BANNISTER RL, 1999, T ASME, V121, P38 BROOMFIELD RW, 1998, T ASME, V120, P595 DECHAMPS PJ, 1998, J ENG GAS TURB POWER, V120, P350 FORD DA, 1999, T ASME, V121, P138 FURUHATA T, 1998, P 11 INT HEAT TRANSF, V7, P283 FUSHITANI K, 1997, J CHEM ENG JPN, V30, P580 HIRATA M, 1999, PLANT ENG APR, P13 ISHII J, 1999, J GAS TURBINE SOC JA, V27, P161 ITOH Y, 1998, J SOC MATER SCI JPN, V47, P665 KACHI T, 1997, KAGAKU KOGAKU RONBUN, V23, P928 KATO Y, 1996, J CHEM ENG JPN, V29, P669 KITANO Y, 1998, CHEM ENG JAPAN, V62, P234 KOBAYASHI M, 1998, P CSME FOR 1998 TOR, V1, P62 KOROBITSYN M, 1999, P 36 NAT HEAT TRANSF, P683 KURZKE J, 1999, T ASME, V121, P6 LI SC, 1997, J ENG GAS TURB POWER, V119, P836 LIOR N, 1997, P 1997 IJPGC DENV US, V1, P431 LIOR N, 1998, P AIAA ASME THERM HE, V4, P33 MALLAMPALLI HP, 1998, J ENG GAS TURB POWER, V120, P703 NAKATA T, 1996, J ENG GAS TURB POWER, V118, P534 SHINODA M, 1998, CHEM ENG J, V71, P207 SUGIYAMA Y, 1997, AICHE 97 LA US, E255 TANAKA R, 1998, P 2 INT S ADV EN CON, P320 TERADA H, 1999, JAPAN SOC ENERGY RES, V20, P167 TSUKAGOSHI K, 1998, J GAS TURBINE SOC JP, V25, P2 WAKU Y, 1999, J GAS TURBINE SOC JA, V27, P65 WITZANI M, 1996, J ENG GAS TURB POWER, V118, P353 YAMAMOTO S, 1998, T JAPAN SOC MECH ENG, V64, P2424 YAMAMOTO T, 1997, ENERG CONVERS MANAGE, V38, P1093 YAMAZAKI Y, 1999, J SOC MATER SCI JPN, V48, P159 YOKOYAMA R, 1996, J ENG GAS TURB POWER, V118, P803 YOSHIDA H, 1998, T JAPAN SOC MECH ENG, V64, P4088 YOSHIDA T, 1993, J GAS TURBINE SOC JA, V20, P4 NR 39 TC 1 PU SOC CHEMICAL ENG JAPAN PI BUNKYO KU TOKYO PA KYORITSU BUILDING 4-16-19 KOHINATA, BUNKYO KU TOKYO, 112, JAPAN SN 0386-216X J9 KAGAKU KOGAKU RONBUNSHU JI Kag. Kog. Ronbunshu PD MAR PY 2000 VL 26 IS 2 BP 142 EP 150 PG 9 SC Engineering, Chemical GA 305HN UT ISI:000086533600002 ER PT J AU Ivanov, VV Ferguson, WG TI The peculiarities of tungsten's influence on phase transformations and mechanical properties of the directionally solidified HCR nickel-base alloy SO HIGH TEMPERATURE MATERIALS AND PROCESSES LA English DT Article AB The application of the directional solidification (DS) increases the life of turbine blades. But this technology demands a new alloying approach, especially for the nickel-base, hot corrosion resistant (HCR) alloys. Such an approach was undertaken in this investigation. The influence of tungsten on the microstructure, phase content, phase transformations, and mechanical properties of the HCR nickel-base alloys were studied both in equiaxially and directionally solidified conditions. Tungsten content was varied between 3 to 9%. Samples with equiaxially and directionally solidified structures were obtained in a High Gradient Directional Solidification Unit with the liquid metal coolant (LMC). The LMC was molten aluminium. It was shown that tungsten has the effect of strengthening the dendrites, which further promotes the DS. The maximum mechanical properties of the directionally solidified alloy were obtained at tungsten content of 7% versus 5% for the conventionally solidified alloy. C1 Univ Auckland, Dept Chem & Mat Engn, Auckland 1, New Zealand. RP Ivanov, VV, Univ Auckland, Dept Chem & Mat Engn, Auckland 1, New Zealand. CR ERICKSON JS, 1974, HIGH TEMPERATURE MAT, P315 FLEMINGS M, 1977, SOLIDIFICATION PROCE IVANOV VV, 1983, NSI T IVANOV VV, 1986, ALL UN SCI ENG C PHY, P45 ODING IA, 1958, THEORY CREEP ENDURAN POLLOCK TM, 1996, METALL MATER TRANS A, V27, P1081 SAIGA K, 1977, KIKAY NO KANKU, V1, P191 SIMS CT, 1976, HEAT RESISTANT ALLOY USMANSKIY YS, 1982, CRYSTALLOGRAPHY ROEN VERTOGRDSKIY VA, 1984, HEAT RESISTANT HEAT, P23 ZVEZDIN YI, 1992, C MECH BEHAV MAT, V6, P111 NR 11 TC 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-6455 J9 HIGH TEMP MATER PROCESS JI High Temp. Mater. Process. PD MAR PY 2000 VL 19 IS 2 BP 101 EP 110 PG 10 SC Materials Science, Multidisciplinary GA 300GE UT ISI:000086243900004 ER PT J AU Troshchenko, VT Prokopenko, AV TI Fatigue strength of gas turbine compressor blades SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE fatigue; fatigue crack growth; defects; residual stress; compressor blades AB An experimental procedure has been developed for the investigation of fatigue and crack growth resistance of materials and real compressor blades. Methods for the determination of stress intensity factors in specimens and in blades with cracks have been justified. Investigations have been performed into the influence of manufacturing residual stresses and surface defects in the form of simulators of dents, corrosion pits, and nonmetallic inclusions on fatigue strength of steels and a titanium alloy. The characteristics of the material crack growth resistance have been studied considering the effect of the medium (sea water) and stress ratio in a cycle, as well as fatigue strength of newly-manufactured blades and those after being in operation. Specific features of fatigue crack propagation in blades have been considered and a method for predicting the life of blades with cracks has been justified. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Acad Sci Ukraine, Inst Problems Strength, UA-252014 Kiev 14, Ukraine. RP Troshchenko, VT, Natl Acad Sci Ukraine, Inst Problems Strength, 2 Timiryazevskaya Str, UA-252014 Kiev 14, Ukraine. CR GRANDT AF, 1972, ASTM STP, V513, P37 PARIS PC, 1964, FATIGUE INTERDISCIPL PODILCHUK Y, 1979, 3 DIMENSIONAL PROBLE PROKOPENKO AV, 1980, STENGTH MAT, V12, P107 PROKOPENKO AV, 1981, STRENGTH MAT, V13, P518 SADOWSKY M, 1944, J APPL MECH, V16, P149 TROSHCHENKO VT, 1981, PREDICTION LIFE GTE, V112 TROSHCHENKO VT, 1981, STRENGTH MAT, V13, P401 TROSHCHENKO VT, 1981, STRENGTH MAT, V13, P477 TROSHCHENKO VT, 1987, CRACK RESISTANCE MET TROSHCHENKO VT, 1996, STRENGTH MAT, V18, P1 NR 11 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD JUN PY 2000 VL 7 IS 3 BP 209 EP 220 PG 12 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 289GF UT ISI:000085611600006 ER PT J AU Naeem, M Singh, R Probert, D TI Implications of engine's deterioration upon an aero-engine HP turbine blade's thermal fatigue life SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE engine deterioration; equivalent full thermal cycle; thermal fatigue; turbine's entry temperature AB Possessing a better knowledge of the impacts of engine deterioration upon an aircraft's performance as well as its fuel and component life usage, helps the users make wiser management decisions and hence achieve improved engine utilization. For a military aircraft, using a computer performance simulation, the consequences of engine deterioration on a high pressure turbine blade's thermal fatigue life are predicted. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 PAF Base Faisal, Cent Tech Dev Unit, Karachi, Pakistan. Cranfield Univ, Sch Mech Engn, Cranfield MK43 0AL, Beds, England. RP Naeem, M, PAF Base Faisal, Cent Tech Dev Unit, Karachi, Pakistan. CR ARVANTIS ST, 1987, J ENG GAS TURB POWER, V109, P107 BREITKOPF GE, 1994, CP368 AGARD COOKSON RA, 1996, SMEPPARAC2245 FOO WP, 1992, J ENG GAS TURB POWER, V114, P275 FUJINO M, 1979, P 3 INT C CAMBR ENGL HALFORD GR, 1976, ASTM STP, V612, P239 HARRISON GF, 1991, ACRO ENGINE RELIABIL, V5, P1 JASKE CE, 1976, ASTM STP, V612, P170 MCNIGHT RL, 1982, AIAA SAE ASME JOINT MCYADYEN N, 1987, GTL7246TR1 NAEEM M, 1998, APPL ENERG, V59, P125 NAEEM M, 1998, APPL ENERG, V60, P115 NAEEM M, 1998, APPL ENERG, V60, P185 NAEEM M, 1999, INT J FATIGUE, V21, P831 NAEEM M, 1999, THESIS CRANFIELD U PEJSA PN, 1986, J ENG GAS TURB POWER, V108, P504 SALLEE GP, 1980, CR15925 NASA SALLEE GP, 1980, NASACR135448 SPERA DA, 1969, TND5489 NASA STEVENSON JD, 1995, 12 INT S AIRBR ENG M WILSON DA, 1986, J ENG GAS TURB POWER, V108, P396 WU FE, 1994, THESIS CRANFIELD U NR 22 TC 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD FEB PY 2000 VL 22 IS 2 BP 147 EP 160 PG 14 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 286PJ UT ISI:000085454100006 ER PT J AU Zhou, S Turnbull, A TI Influence of pitting on the fatigue life of a turbine blade steel SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE corrosion-fatigue; pitting; short cracks; 12Cr stainless steel ID CRACK INITIATION; CORROSION; PROPAGATION; PREDICTION; STRESS; GROWTH AB The role of pits as stress raisers and their influence on fatigue life has been investigated for a 12Cr turbine blade material. A particular feature of this work was the establishment of an electrochemical procedure for generating pits with 'controlled' pit depth and low density. Pits grown under laboratory conditions were partially spherical in shape and simulated, in general appearance, those observed in service. In terms of the threshold stress intensity factor, the results supported the concept of pits acting as effective cracks of the same depth, provided that a short crack model based on an effective crack length is used. C1 Natl Phys Lab, Teddington TW11 0LW, Middx, England. RP Zhou, S, Natl Phys Lab, Teddington TW11 0LW, Middx, England. CR *ASTM, 1994, 1994 ANN BOOK ASTM S, P465 *BRIT STAND, 1993, 3518 BS *BRIT STAND, 1997, 4287 BS ISO AKID R, 1997, AM SOC TEST MATER, V1298, P3 BUXTON DC, 1993, CORROSION DEFORMATIO, P901 CAMERON AD, 1981, INT J FATIGUE, V3, P9 CHARKRAVARY S, 1993, P ASM 1993 MAT C MAT, P135 COULON PA, 1993, WORKSH P PAL ALT CAL DAWLING MH, 1977, ASTM STP, V637, P97 DOLLE H, 1980, MET T A, V11, P159 DUQUESNAY DL, 1986, BEHAV SHORT FATIGUE, P323 EBARA R, 1990, ISIJ INT, V30, P535 EBARA R, 1993, WORKSH P PAL ALT CA ELHADDAD MH, 1979, ASME, V101, P42 ELHADDAD MH, 1980, INT J FRACTURE, V16, P15 ELHADDAD MH, 1981, J ENG MATER TECHNOL, V103, P91 GABETTA G, 1992, FATIGUE FRACT ENG M, V15, P1101 GABETTA G, 1994, MAT ADV POWER ENG 1, P199 HAUK VM, 1982, METALL T A, V13, P1239 HUDAK SJ, 1981, T ASME, V103, P26 ISHIHARA S, 1995, FATIGUE FRACT ENG M, V18, P1311 JAFFEE RI, 1981, WORKSH P PAL ALT CAL KAWAI S, 1985, FATIGUE FRACT ENG M, V8, P115 KITAGAWA H, 1976, P 2 INT C MECH BEH M, P627 KONDA Y, 1989, INT C EV MAT PERF SE, V1, P135 KONDO Y, 1989, CORROSION, V45, P7 LEBEDEVA AI, 1992, THERM ENG, V39, P69 LINDLEY TC, 1982, MET TECHNOL, V9, P135 LUKAS P, 1982, FATIGUE THRESHOLDS, P737 MCINTYRE P, 1989, BR CORR J, V24, P103 MILLER KJ, 1996, P ROY SOC LOND A MAT, V452, P1411 QVARFORT R, 1988, CORROS SCI, V28, P135 SHALABY HM, 1996, CORROSION, V52, P262 SMITH RA, 1978, INT J MECH SCI, V20, P201 SPEAKES GM, 1987, P I MECH ENG C REF L, P315 SPEIDEL MO, 1991, STRESS CORROSION CRA, P343 SURESH S, 1984, INT MET REV, V29, P445 TOYAMA K, 1989, INT C EV MAT PERF SE, V1, P105 TURNBULL A, 1996, CORROSION STANDARDS, V2, P147 WEI RP, 1997, C REC ADV CORR FAT S NR 40 TC 7 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG MATER STRUC JI Fatigue Fract. Eng. Mater. Struct. PD DEC PY 1999 VL 22 IS 12 BP 1083 EP 1093 PG 11 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 281VD UT ISI:000085180700006 ER PT J AU Ronold, KO Larsen, GC TI Reliability-based design of wind-turbine rotor blades against failure in ultimate loading SO ENGINEERING STRUCTURES LA English DT Article DE wind climate; wind turbines; ultimate loading; structural reliability; code calibration; partial safety factors AB A probabilistic model for analysis of the safety of a wind-turbine rotor blade against failure in ultimate loading is presented. Only failure in flapwise bending during the normal operating condition of the wind turbine is considered. The model is based on an extreme-value analysis of the load response process in conjunction with a stochastic representation of the governing tensile strength of the rotor blade material. The model is applied to an analysis of the reliability of a site-specific wind turbine of a prescribed make. A 20 yr design life is considered. The probability of failure in flapwise bending of the rotor blade is calculated by means of a first-order reliability method, and contributions to this probability from all local maxima of the load response process over the operational life are integrated. It is demonstrated how the reliability analysis results can be used to calibrate partial safety factors for load and resistance for use in conventional deterministic design. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Norske Veritas, N-1322 Hovik, Norway. Riso Natl Lab, Wind Energy & Atmospher Phys Dept, DK-4000 Roskilde, Denmark. RP Ronold, KO, Norske Veritas, POB 300, N-1322 Hovik, Norway. CR BJERAGER P, 1988, P 5 INT C BEH OFFSH ECHTERMEYER AT, 1996, DESIGN COMPOSITE STR, CH3 MADSEN HO, 1986, METHODS STRUCTURAL S RICE SO, 1944, BELL SYST TECH J, V23, P282 RICE SO, 1945, BELL SYST TECH J, V24, P46 RONOLD KO, 1991, J ENG MECH-ASCE, V117, P2101 RONOLD KO, 1993, THESIS STANFORD U ST TVEDT L, 1989, 892023 NORSK VER WEN YK, 1987, PROBALISTIC ENG MECH, V2, P156 WINTERSTEIN SR, 1988, J ENG MECH-ASCE, V114, P1772 WINTERSTEIN SR, 1994, P BEH OFFSH STRUCT C NR 11 TC 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-0296 J9 ENG STRUCT JI Eng. Struct. PD JUN PY 2000 VL 22 IS 6 BP 565 EP 574 PG 10 SC Engineering, Civil GA 275XL UT ISI:000084845400001 ER PT S AU Zheng, Y Han, Y TI Influencing factors of stress rupture at 750 degrees C temperature for cast nickel base superalloy K403 SO CREEP AND FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES SE KEY ENGINEERING MATERIALS LA English DT Article DE cast superalloy; intermediate temperature stress-rupture; heat treatment; microstructure; deformation mechanism AB The standard heat treatment of cast nickel-base superalloy K403 is the solid solution treatment of 1210 degrees C/4h, air-cooling. It is very difficult to meet the requirements of the intermediate temperature stress-rupture life regulated by Aviation Standard HB5155. In order to resolve the above problem, some factors influencing intermediate stress-rupture life have been explored. The results showed that the intermediate temperature stress-rupture properties impaired by treatment of 1210 degrees C/4h were due to precipitation of too small gamma(.) phase (< 0.2 mu m) in grains and absence of the secondary carbides at grain boundaries. The dendritic pattern appears at the fracture surface and there is no slip trace at the gauge length part of specimens treated by 1210 degrees C/4h, but the crystallographic plane at fracture surface and the extensive slip can be observed for the specimens treated by 1180 degrees C/4h. TEM results have shown that during intermediate temperature deformation the dislocation of 1/2 < 110 > moves to the interface of gamma / gamma(.) and cuts gamma(.) phase to form the high energy antiphase boundaries. The finer gamma(.) can be cut and passed easily by dislocation and has a poor resistance to intermediate temperature creep, The finer dendrites and the microstructure containing intergranular M6C carbide with envelope of gamma(.) and residual coarse gamma(.) within grains were beneficial. Therefore high cooling rate during solidification and partial solid solution treatment of 1180 degrees C/4h are suitable for a turbine blade alloy K403. C1 Inst Aeronaut Mat, Beijing 100095, Peoples R China. RP Zheng, Y, Inst Aeronaut Mat, POB 81, Beijing 100095, Peoples R China. CR *AV IND STAND, 1988, HB515588 AV IND STAN DOHERTY JE, 1974, CAN METALL Q, V13, P229 MAXWELL DH, 1975, METALLURGIA, P332 TIEN JK, 1972, METALL T, V3, P2157 ZHENG YR, 1983, HJB830117 CHIN AER S NR 5 TC 0 PU TRANSTEC PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 2000 VL 171-1 BP 561 EP 568 PG 8 SC Materials Science, Ceramics; Materials Science, Composites GA BP25R UT ISI:000084507700072 ER PT J AU Noda, M Flay, RGJ TI A simulation model for wind turbine blade fatigue loads SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article DE wind turbine; blade; fatigue life; aerodynamic load; fatigue damage; rainflow counting; computer simulation AB The paper describes a horizontal axis wind turbine time domain simulation and fatigue estimation program written using the Delphi(TM) language. The program models the flapwise motion of a single rotor blade to determine the blade-root fatigue damage of a medium size wind turbine. The effects of turbulence intensity, mean wind speed, wind shear, vertical wind component, dynamic stall, stall hysteresis, and blade stiffness were examined. When all these effects were simulated it is found that a reduction in life of about 2 occurs between a low wind speed low turbulence intensity site, compared to a high wind speed high turbulence intensity site. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Auckland, Dept Mech Engn, Auckland 1, New Zealand. RP Flay, RGJ, Univ Auckland, Dept Mech Engn, Auckland 1, New Zealand. CR COLLECUTT GR, 1994, THESIS U AUCKLAND CONNELL JR, 1982, SOL ENERGY, V29, P363 ECHTERMEYER AT, DESIGN COMPOSITES FA, P33 EGGLESTON DM, 1987, WIND TURBINE ENG DES HANSEN AC, 1993, ANNU REV FLUID MECH, V25, P115 MINER MA, 1945, J SOL ENERGY ENG, V117, P194 PETERSEN SM, 1990, WIND TURBINE TEST VE PUTNAM GC, 1948, POWER WIND VANLEISHOUT P, 1996, NEW EMERGING RENEWAB YEZNASNI A, 1992, J WIND ENG IND AEROD, V39, P187 NR 10 TC 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AERODYN JI J. Wind Eng. Ind. Aerodyn. PD NOV-DEC PY 1999 VL 83 BP 527 EP 540 PG 14 SC Engineering, Civil; Mechanics GA 260FJ UT ISI:000083938600045 ER PT J AU Price, JR Jimenez, O Faulder, L Edwards, B Parthasarathy, V TI Ceramic stationary gas turbine development program - Fifth annual summary SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB A program is being performed under the sponsorship of the United States Department of Energy Office of Industrial Technologies, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of metallic hot section components with ceramic parts. The program focuses on design fabrication, and testing of ceramic components, generating a materials properties data base, and applying life prediction and nondestructive evaluation (NDE). The development program is being performed by a team led by Solar Turbines Incorporated, and which includes suppliers of ceramic components, U.S. research laboratories, and an industrial cogeneration end user. The Solar Centaur 50S engine ri qs selected for the development program. The program goals included an increase in the turbine rotor inlet temperature (TRIT) from 1010 degrees C (1850 degrees F) to 1121 degrees C (2050 degrees F), accompanied by increases in thermal efficiency and output power. The performance improvements are attributable to the increase in TRIT and the reduction in cooling air requirements for the ceramic parts. The ceramic liners are also expected to lower the emissions of NOx and CO. Under the program uncooled ceramic blades and nozzles have been inserted for currently cooled metal components in the first stage of the gas producer turbine. The louvre-cooled metal combustor liners have been replaced with uncooled continuous-fiber reinforced ceramic composite (CFCC) liners. Modifications have been made to the engine hot section to accommodate the ceramic parts. To date, all first generation designs have been completed. Ceramic components have been fabricated, and are being tested in rigs and in the Centaur 50S engine. Field testing at an industrial co-generation sire was started in May 1997. This paper will provide an update of the development work and details of engine testing of ceramic components under the program. C1 Solar Turbines Inc, San Diego, CA 92186 USA. RP Price, JR, Solar Turbines Inc, 2200 Pacific Highway, San Diego, CA 92186 USA. CR *US DEP EN, 1994, COMPR PROGR PLAN ADV FAULDER L, 98GT528 ASME JIMENEZ O, 1998, 98GT529 ASME NORTON PF, 1995, 95GT383 ASME SIMPSON JF, 1997, 1997 AM CER SOC ECD SMITH KO, 1996, 96GT318 ASME SMITH KO, 1997, 97GT156 ASME VANROODE M, 1993, 93GT306 ASME VANROODE M, 1994, 94GT313 ASME VANROODE M, 1995, 95GT459 ASME VANROODE M, 1996, 96GT460 ASME VANROODE M, 1997, 97GT317 ASME NR 12 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1999 VL 121 IS 4 BP 586 EP 592 PG 7 SC Engineering, Mechanical GA 250ZH UT ISI:000083419800002 ER PT J AU Henderson, P Komenda, J TI A metallographic technique for high temperature creep damage assessment in single crystal alloys SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID SUPER-ALLOY AB The use of single crystal (SX) nickel-base superalloys will increase in the future with the introduction of sx blades into large gas turbines far base-load electricity production. Prolonged periods of use at high temperatures may cause creep deformation and the assessment of damage can give large financial savings. A number of techniques can be applied for life assessment, e.g., calculations based an operational data, nondestructive testing or material interrogation, but because of the uncertainties involved the techniques are often used in combination. This paper describes a material interrogation (metallographic) technique far creep strain assessment in SX alloys. Creep tests have been performed at 950 degrees C on the SX alloy CMSX-4 and quantitative microstructural studies performed on specimens interrupted at various levels of strain. It was found that the strengthening gamma'-particles, initially cuboidal in shape, coalesced to form large plates or rafts normal to the applied stress. The gamma-matrix phase also formed plates. CMSX-4 contains similar to 70 vol % gamma'-particles and after creep deformation the microstructure turned itself inside out, i.e., the gamma "matrix" became the isolated phase surrounded by the gamma'-"particles." This can cause problems for computerized image analysis, which in this case, were overcome with the choice of a suitable measurement parameter. The rafts reached their maximum length before 2 percent strain, but continued to thicken with increasing strain. Although of different dimensions, the aspect ratios (length/thickness ratio) of the gamma-prime rafts and the gamma plates were similar at similar levels of strain, increasing from similar to 1 at zero strain to a maximum of similar to 3 at about 1-2 percent strain. Analysis of microstructural measurements from rafting studies on SX alloys presented in the literature showed that the aspect ratios of the gamma and gamma'-phases were similar and that at a temperature of 950-1000 degrees C a maximum length/thickness ratio of about 2.5-3.5 is reached at 1 to 2 percent creep strain. Measurement of gamma-prime raft or (or gamma plate) dimensions on longitudinal sections of blades is thus a suitable method for high temperature creep damage assessment of SX alloys. This gives a considerable advantage over conventional Ni-base superalloys whose microstructures are usually very stable with respect to increasing creep strain. C1 Vattenfall Energisyst AB, S-16216 Stockholm, Sweden. Swedish Inst Met Res, S-11428 Stockholm, Sweden. RP Henderson, P, Vattenfall Energisyst AB, POB 528, S-16216 Stockholm, Sweden. CR CASTILLO R, 1988, P SUP 1988, P805 HENDERSON P, 1999, SCRIPTA MATER, V40, P229 HENDERSON PJ, 1985, SCRIPTA METALL, V19, P99 HENDERSON PJ, 1988, SCRIPTA METALL, V22, P1103 HENDERSON PJ, 1997, P ADV TURB MAT DES E, P63 KARLSSON SA, 1995, P BALTICA 3 INT C PL, P333 KOUL AK, 1988, METALL TRANS A, V19, P2049 MACKAY RA, 1983, SCRIPTA METALL, V17, P1217 MACKAY RA, 1985, METALL TRANS A, V16, P1969 MUGHRABI H, 1994, P 10 INT C STRENGTH, P705 MUKHERJI D, 1997, ACTA MATER, V45, P3143 NATHAL MV, 1983, SCRIPTA METALL, V17, P1151 NATHAL MV, 1987, MATER SCI ENG, V85, P127 PEARSON DD, 1980, P 4 INT S SUP 7 SPRI, P513 PERSSON C, P SUP 1992, P867 POLLOCK TM, 1994, ACTA METALL MATER, V42, P1859 VERON M, 1997, ACTA MATER, V45, P3277 NR 17 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1999 VL 121 IS 4 BP 683 EP 686 PG 4 SC Engineering, Mechanical GA 250ZH UT ISI:000083419800016 ER PT J AU Affeldt, EE TI Influence of an aluminide coating on the TMF life of a single crystal nickel-base superalloy SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID BEHAVIOR; FATIGUE AB TMF tests were conducted with bare and aluminide coated single crystal nickel-based superalloy specimens. Temperature cycling was between 400 degrees C and 1100 degrees C with a phase shift (135 deg) that is typical for damaged locations on turbine blades. Stress response is characterized by a constant range and the formation of a tensile mean stress as a result of relaxation in the high temperature part of the cycle which is in compression. Bare specimens showed crack initiation from typical oxide hillocks. Coated specimens showed life reduction with respect to the bare ones caused by brittle cracking of the coating in the low temperature part of the cycle. Isothermal bending tests of coated specimens confirmed the low ductility of the coating at temperatures below 600 degrees C but quantitative correlation with the TMF test results failed. C1 MTU Motoren & Turbinen Union Munchen, D-80976 Munich, Germany. RP Affeldt, EE, MTU Motoren & Turbinen Union Munchen, Postfach 50 06 40, D-80976 Munich, Germany. CR BRESSERS J, 1996, AGARDCP569 BRESSERS J, 1996, ASTM STP, V1263, P56 CHATAIGNER E, 1996, ASTM STP, V1263, P3 FLEURY E, 1990, HIGH TEMPERATURE MAT, P1007 HEINE JE, 1989, WRDCTR874102 UN TECH, P13 JOHNSON PK, 1997, IN PRESS J ENG MAT T LINDE L, 1994, MAT ADV POWER ENG 2, P1367 MARTINEZESNAOLA JM, 1996, ASTM STP, V1263, P68 TOTEMEIER TC, 1993, MAT SCI ENG A-STRUCT, V169, P19 TOTEMEIER TC, 1996, METALL MATER TRANS A, V27, P353 VASSEUR E, 1994, MAT SCI ENG A-STRUCT, V184, P1 NR 11 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1999 VL 121 IS 4 BP 687 EP 690 PG 4 SC Engineering, Mechanical GA 250ZH UT ISI:000083419800017 ER PT J AU Zrnik, J Zitnansky, M Hazlinger, M TI Structure dependence of creep and creep-fatigue deformation and fracture process of single crystal nickel base superalloy SO KOVOVE MATERIALY-METALLIC MATERIALS LA Slovak DT Article ID TEMPERATURE; ALLOY AB The effect of different initial microstructures of single crystal nickel base superalloy, frequently used as blade material for gas turbines, defined by gamma prime morphology, has been investigated wider the creep and creep-fatigue conditions at 900 degrees C and 500 MPa. For cyclic loading the wave form of stress as a function of time was of trapezoidal shape with a hold time of 10 s at the upper stress level. The fracture life-time and cycles to fracture were criteria being considered to evaluate deformation behaviour of alloy defined by different structure states wider complex creep-fatigue loading. The TEM study of thin foils cut from fractured specimens was used to analyze the deformation mechanism in strengthened matrix in dependence on initial alloy structure. As the results showed, the higher creep strength was achieved in case of structures with cuboidal gamma prime morphology. However, the introduction of the cyclic stress component onto creep stress resulted in the lifetime reduction in comparison with the simple creep deformation and in modification of the fracture mode morphology. C1 HF TU Kosice, Katedra Nauky Materialoch, Kosice 04001, Slovakia. STU, Mat Technol Fak, Trnava 91724, Slovakia. RP Zrnik, J, HF TU Kosice, Katedra Nauky Materialoch, Pk Komenskeho 11, Kosice 04001, Slovakia. CR CETEL AD, 1988, SUPERALLOYS 1988, P235 ELLISON EG, 1991, FATIGUE FRACT ENG M, V14, P721 KHAN T, 1986, MATER SCI TECH SER, V2, P486 NATHAL MV, 1987, METALL TRANS A, V18, P1961 SUEMITSU T, 1986, T ISIJ, V26 SVETLOV IL, 1992, SCRIPTA METALL MATER, V26, P1535 WANG X, 1993, SCRIPTA METALL MATER, V28, P401 YANG ZA, 1988, MAT SCI ENG A-STRUCT, V101, P65 ZRNIK J, 1992, KOVOVE MATER, V30, P325 ZRNIK J, 1993, 6 K MAR LAZN, P149 NR 10 TC 0 PU REDAKCIA KOVOVE MATERIALY PI BRATISLAVA 38 PA UL RACIANSKA 75, PO BOX 95, 830 08 BRATISLAVA 38, SLOVAKIA SN 0023-432X J9 KOVOVE MATER-METAL MATER JI Kov. Mater.-Met. Mater. PY 1999 VL 37 IS 4 BP 246 EP 255 PG 10 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 237QU UT ISI:000082668200002 ER PT J AU Naeem, M Singh, R Probert, D TI Implications of engine deterioration for a high-pressure turbine-blade's low-cycle fatigue (LCF) life-consumption SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE cycle-counting; engine deterioration; life to failure; low-cycle fatigue; rainflow ID RAINFLOW AB As a result of experiencing a deterioration of efficiency and/or mass flow, an aero-engine will automatically adjust to a different set of operating characteristics; frequently resulting in changes of rpm and/or turbine entry-temperature in order to provide the same thrust. As such, the stresses that the engine is subjected to will change land thereby alter the blade's low-cycle fatigue-life consumption) relative to that for an engine suffering no deterioration (i.e. in the jargon-a 'clean' engine). Rises in the turbine's entry-temperatures and the high-pressure turbine's rotational-speed result in greater rates of creep and fatigue damage being incurred by the hot-end components and thereby higher engine's life-cycle costs. Possessing a better knowledge of the effects of engine deterioration upon the aircraft's performance, as well as fuel and life usages, helps the users to take wiser management decisions and hence achieve improved engine utilization. For a military aircraft, by employing a bespoke computer simulation, the consequences of engine deterioration on a high-pressure turbine blade's low-cycle fatigue-life consumption are predicted. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Cranfield Univ, Sch Mech Engn, Cranfield MK43 0AL, Beds, England. RP Naeem, M, Cranfield Univ, Sch Mech Engn, Cranfield MK43 0AL, Beds, England. CR *ESDU, 1995, FATIGUE ENDURANCE DA, V2 BASQUIN OH, 1910, P AM SOC TEST MATER, V10, P625 COFFIN LF, 1954, T ASME, V76, P931 COOKSON RA, 1996, LECT NOTES COOKSON RA, 1996, SMEPPARAC2269 CRANF CORTEN HT, 1956, INT C FAT MET LOND, P235 DEITRICK CC, 1981, AIAA811367 DOWLING NE, 1972, J MATERIALS JMLSA, V7, P71 DOWNING SD, 1982, INT J FATIGUE, V4, P31 GROVER HJ, 1960, ASTM STP, V274 HALL CL, 1983, ASME, V105, P627 HARRISON GF, 1993, 93043 DRA TR JACKSON P, 1996, JANES WORLDS AIRCRAF JAMES AG, 1968, SAE ADV ENG, V4 KAECHELE LE, 1963, RM3650PR LIU HW, 1959, TND256 NASA LIU HW, 1960, TND647 NASA MANSON SS, 1953, 2933 NACA TN MANSON SS, 1961, P AM SOC TEST MATER, V61, P679 MATSUISHI M, 1968, JAP SOC MECH ENG C F MAY RJ, 1981, AIAA811652 MINER MA, 1945, J APPL MECH, V12, P159 NAEEM M, 1998, APPL ENERG, V59, P125 NAEEM M, 1998, APPL ENERG, V60, P115 NAEEM M, 1998, APPL ENERG, V60, P185 OCONNOR CM, 1988, C P PALMGREN A, 1924, Z VER DTSCH ING, V68, P339 RASKE DT, 1969, ASTM SPEC TECH PUBL, V465, P1 RICHART FE, 1948, P ASTM, V48, P767 RYCHLIK I, 1987, INT J FATIGUE, V9, P119 SPITZER R, 1961, P AM SOC TEST MATER, V61, P719 STABRYLLA RG, 1980, AIAA801115 STEVENSON JD, 1995, ISABE 957077 WATSON P, 1976, J SOC ENV ENG, V15, P3 WETZEL RM, 1977, SAE ADV ENG, V6, P117 WU FE, 1994, THESIS CRANFIELD U U NR 36 TC 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD SEP PY 1999 VL 21 IS 8 BP 831 EP 847 PG 17 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 229EK UT ISI:000082180400010 ER PT J AU de Goeij, WC van Tooren, MJL Beukers, A TI Implementation of bending-torsion coupling in the design of a wind-turbine rotor-blade SO APPLIED ENERGY LA English DT Article DE wind turbine; blade; composite; bending-torsion coupling ID ELASTIC COUPLINGS; BEAMS AB An investigation is performed on the implementation of bending-torsion coupling of a composite wind turbine rotor blade to provide passive pitch-control. Limited passive torsion deformation is realised with a structural coupling between flapwise bending and elastic twist of a constant speed rotor-blade. The blade and skin laminate configuration are analysed with a FEM program, in which a complete blade with spar webs is modelled. This conventional blade configuration has some disadvantages. Therefore alternative design concepts are reviewed, where the coupling plies are restricted to a load-bearing spar, while a softer skin provides for the aerodynamic shape. From additional analysis, it is found that, while for the two alternative design concepts the stress concentrations at the leading edge joint are bypassed, the bending-torsion coupling response is lower. An experiment was performed to validate the calculation methods. The experimental results show good correlation with theoretical predictions. It is recommended to investigate further the fatigue life properties of a glass/carbon hybrid FRP with off-axis fibre orientations. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Delft Univ Technol, Fac Aerosp Engn, Sect Prod Technol, NL-2600 GB Delft, Netherlands. RP de Goeij, WC, Delft Univ Technol, Fac Aerosp Engn, Sect Prod Technol, Kluyverweg 3,POB 5058, NL-2600 GB Delft, Netherlands. CR BACH PW, 1992, C92072 ECN CHANDRA R, 1991, AIAA J, V29, P2197 CHANDRA R, 1991, P0 17 EUR ROT FOR BE CHANDRA R, 1992, COMPOS ENG, V2, P347 COOLS JJ, 1981, SAMPE J, V17 DAHRAN CKH, 1975, ASTM STP, V569, P171 DEGOEIJ WC, 1998, I98047 ECN DESMET BJ, 1994, C94045 ECN DHARAN CKH, 1975, J MATER SCI, V10, P1665 DICKSON RF, 1989, FATIGUE BEHAV HYBR 2 GARFINKLE M, 1994, AEROSPACE AM JUL GJELSVIK A, 1981, THEORY THIN WALLED B JONES RM, 1975, MECH COMPOSITE MAT KARAOLIS NM, 1989, THESIS U READING KOOIJMAN HJT, 1996, I96060 ECN LORENZO L, 1986, ASTM STP, V907, P210 MALLICK PK, 1993, FIBER REINFORCED COM MAYER RM, 1996, MECH ENG PUBLICATION OLDERSMA A, 1992, 91345 NLR TP REIFSNIDER KL, 1991, FATIGUE COMPOSITE MA SUNDARESAN MJ, 1995, ASME, V69, P365 TALREJA R, 1981, P ROY SOC LOND A MAT, V378, P461 VLASOV VZ, 1961, THIN WALLED ELASTIC WEISSHAAR TA, 1987, AIAA ASME ASCE AHS 2 YEE RP, 1995, ASME, V69, P401 NR 25 TC 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0306-2619 J9 APPL ENERG JI Appl. Energy PD JUL PY 1999 VL 63 IS 3 BP 191 EP 207 PG 17 SC Energy & Fuels; Engineering, Chemical GA 222WY UT ISI:000081809400004 ER PT J AU So, RMC Jadic, I Mignolet, MP TI Oncoming alternating vortices SO JOURNAL OF FLUIDS AND STRUCTURES LA English DT Article ID FLUID-STRUCTURE INTERACTIONS; CIRCULAR-CYLINDERS; FORCES; FLOWS; FOIL AB The present investigation examines a simple fluid-structure interaction problem, which is represented by the unsteady response of an airfoil/blade to a Karman vortex street in an inviscid uniform how. Two different cases were examined; one with a rigid airfoil/blade, where the structural stiffness is infinite, another with an elastic blade. In both cases, the how remains attached to the airfoil/blade surface. A time-marching technique solving the Euler equations and a two-degree-of-freedom structural dynamic model is used to examine the interactions between the fluid and the structure. The interactions between the convected vortices and the structure modify the shed wake whose energy, in turn, feeds into the forces and moments acting on the structure. For a rigid airfoil/blade, it is found that the amplitude of the aerodynamic response is not proportional to the density of the oncoming vortex street, but depends on c/d, the ratio of the chord length (c) to the axial spacing (d) of the convected vortices. When the number of vortices per unit length is increased, the amplitudes of the aerodynamic response increase and then decrease even though the density of the vorticity keeps increasing and so is the energy of the excitation wake. Maxima are observed at c/d = 0.5, 1.5 and 2.5. This behaviour is analogous to the structural resonance phenomenon and is labeled "aerodynamic resonance". The existence of such an "aerodynamic resonance" is important to turbomachinery applications where the blade is elastic, the how is unsteady and the shed vortices from the previous row are convected downstream by the mean flow. Thus, "aerodynamic resonance" alone or in conjunction with structural resonance could impact negatively on the fatigue life of turbine blades and their combined effects should be accounted for in blade design. A preliminary attempt to assess this impact has been carried out. It is found that the relative fatigue life of a blade could be reduced by four orders of magnitude as a result. (C) 1999 Academic Press. C1 Hong Kong Polytech Univ, Kowloon, Hong Kong. Arizona State Univ, Tempe, AZ 85287 USA. RP So, RMC, Hong Kong Polytech Univ, Kowloon, Hong Kong. CR ABBOTT IH, 1959, THEORY WING SECTIONS BABAN F, 1991, J FLUID STRUCT, V5, P185 BELANGER F, 1995, AIAA J, V33, P752 BETZ A, 1912, Z FLUGTECHN MOTORLUF, V3, P269 CASADEI F, 1995, COMPUT METHOD APPL M, V128, P231 CHORIN AJ, 1973, J FLUID MECH, V57, P785 CHRISTIANSEN JP, 1973, J COMPUT PHYS, V13, P363 CLEMENTS RR, 1975, PROG AEROSPACE SCI, V16, P129 DIETER GE, 1986, MECH METALLURGY FEIEREISEN JM, 1994, J TURBOMACH, V116, P676 FUNAZAKI K, 1989, UNST AER AER TURB PR, P287 FUNG YC, 1993, INTRO THEORY AEROELA GARRICK JE, 1936, 567 NACA GOPALKRISHNAN R, 1994, J FLUID MECH, V274, P1 HALL KC, 1994, AIAA J, V32, P2426 HARRIS WJ, 1961, METALLIC FATIGUE HODSON HP, 1996, 96GT494 ASME JADIC I, 1997, THESIS AR STAT U MEC JADIC I, 1998, J FLUID STRUCT, V12, P631 KATZMAYR R, 1922, TM147 NACA KEMP NH, 1955, J AERONAUT SCI, V22, P478 KNOLLER R, 1909, FLUG MOTORTECHNIK WI, V3, P1 KNOLLER R, 1913, Z FLUGTECHN MOTORLUF, V4, P13 LALANNE M, 1983, MECH VIBRATIONS ENG MAJJIGI RK, 1984, NASACR174849, V1 MIGNOLET MP, 1994, P 35 STRUCT STRUCT D, P1628 NAUDASCHE E, 1994, FLOW INDUCED VIBRATI OLSON LG, 1985, COMPUT STRUCT, V21, P21 POLING DR, 1989, AIAA J, V27, P694 SCHMIDT W, 1960, DTSCH FLUGTECHNIK, V4, P350 SCHMIDT W, 1965, Z FLUGWISSENSCHAFTEN, V13, P472 SO RMC, 1981, J FLUID MECH, V105, P397 STREITLIEN K, 1996, AIAA J, V34, P2315 XING JT, 1991, P ROY SOC LOND A MAT, V433, P235 YAO ZX, 1989, 892225 AIAA YAO ZX, 1993, THESIS ARIZONA STATE YAO ZX, 1995, INT FOR AER STRUCT D ZIENKIEWICZ OC, 1978, INT J NUMER METH ENG, V13, P1 NR 38 TC 8 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0889-9746 J9 J FLUID STRUCTURE JI J. Fluids Struct. PD MAY PY 1999 VL 13 IS 4 BP 519 EP 548 PG 30 SC Engineering, Mechanical; Mechanics GA 221LK UT ISI:000081728400006 ER PT J AU Chan, KS Cheruvu, NS Leverant, GR TI Coating life prediction for combustion turbine blades SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID CYCLIC OXIDATION AB A life prediction method for combustion turbine blade coatings has been developed by modeling coating degradation mechanisms including oxidation, spallation, and aluminum loss due to inward diffusion. Using this model, the influence of cycle time on coating life is predicted for GTD-111 coated with an MCrAlY, PtAl, or aluminide coating. The results are used to construct a coating life diagram that depicts failure and safe regions for the coating in a log-log plot of number of startup cycle versus cycle time. The regime where failure by oxidation, spallation, and inward diffusion dominates is identified and delineated from that dominated by oxidation and inward diffusion only. A procedure for predicting the remaining life of a coating is developed. the utility of the coating life diagram for predicting the failure and useful life of MCrAlY, aluminide, or PtAl coatings on the GTD-111 substrate is illustrated and compared against experimental data. C1 SW Res Inst, Mech & Mat Engn Div, EPRI, Mat Ctr Combust Turbines, San Antonio, TX 78228 USA. RP Chan, KS, SW Res Inst, Mech & Mat Engn Div, EPRI, Mat Ctr Combust Turbines, PO Drawer 28510, San Antonio, TX 78228 USA. CR CHAN KS, 1997, 97GT389 ASME CHAN KS, 1997, METALL MATER TRANS A, V28, P411 CHERUVU NS, 1998, 1998 ASME TURBO EXPO KIRKALDY JS, 1970, ADV MATER RES, V4, P55 LEE KC, 1987, J KOREAN MED SCI, V2, P19 LOWELL CE, 1991, OXID MET, V36, P81 NESBITT JA, 1984, 83738 NASA TM LEW RE NESBITT JA, 1984, THIN SOLID FILMS, V119, P281 NESBITT JA, 1989, DIFFUSION ANAL APPL, P307 NESBITT JA, 1989, J ELECTROCHEM SOC, V136, P1518 NESBITT JA, 1993, STRUCTURAL INTERMETA, P601 PROBST HB, 1988, J MET, V40, P18 NR 12 TC 10 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1999 VL 121 IS 3 BP 484 EP 488 PG 5 SC Engineering, Mechanical GA 220AB UT ISI:000081640500015 ER PT J AU Kakehi, K TI Influence of crystallographic orientation on the strength of Ni-base superalloy single crystals at temperatures above the peak temperature SO JOURNAL OF THE JAPAN INSTITUTE OF METALS LA Japanese DT Article DE single crystals; nickel-base superalloy; crystallographic orientation; creep strength; elevated-temperature tensile strength; viscous slip; octahedral slip; cube slip ID MECHANICAL-PROPERTIES; CREEP-PROPERTIES; SRR-99; ALLOYS; CMSX-2 AB The yield strength of high strength nickel-base superalloys for gas turbine blades increases with increasing temperature up to a peak temperature (650 similar to 800 degrees C). The influence of crystallographic orientation on the high-temperature mechanical properties of single-crystal nickel-base superalloys was investigated by a systematic study of the deformation mechanism at a temperature above the peak temperature. Tensile and creep tests were carried out at 900 degrees C. Initial tensile orientations were selected over a wide range on the standard stereographic triangle. In the tensile test, Schmid's law, based on an assumption of {111}[(1) over bar 01] slip system, broke down because of the cross slip of superlattice dislocation pairs from the unique slip plane, The effect of both cube slip in the gamma' phase and by-passing mechanism is to give a suppression of the yield strength in [(1) over bar 11] orientation. In the creep test, it was found that the orientations in which the operation of {111}[(1) over bar 01] slip systems is unstable exhibited the planar slip fracture surfaces and low ductilities; on the contrary, the stable-slip orientations exhibited the large ductilities, and the specimen with [(1) over bar 11] orientation exhibited the Longest rupture life as a result of a low Schmid factor for the {111}[(1) over bar 01] slip systems. Therefore, creep deformation occurs primarily by viscous slip of the relaxed a/2[(1) over bar 01] dislocation pairs controlled by climb of the anti phase boundary. Furthermore, the operation of cube slip in the gamma' phase, as well as octahedral slip which shears both gamma'-gamma phases, gave a good account of the orientation dependence of creep strength. C1 Tokyo Metropolitan Univ, Grad Sch Engn, Dept Mech Engn, Hachioji, Tokyo 1920397, Japan. RP Kakehi, K, Tokyo Metropolitan Univ, Grad Sch Engn, Dept Mech Engn, Hachioji, Tokyo 1920397, Japan. CR CARON P, 1988, SUPERALLOYS 1988, P215 CARON P, 1989, STRENGTH METALS ALLO, P893 COPLEY SM, 1967, T METALL SOC AIME, V239, P977 COPLEY SM, 1967, T TMS AIME, V239, P984 COURBON J, 1991, PHIL MAG LETT, V63, P73 DIETER GE, 1986, MECH METALLURGY, P132 FELLERKNIEPMEIE.M, 1992, METALL T A, V23, P99 FELLERKNIEPMEIER M, 1989, MAT SCI ENG A-STRUCT, V113, P191 FELLERKNIEPMEIER M, 1989, METALL TRANS A, V20, P1233 KAKEHI K, IN PRESS METALL MAT KEAR BH, 1969, SCRIPTA METALL, V3, P123 KEAR BH, 1969, SCRIPTA METALL, V3, P455 KEAR BH, 1969, T AM SOC MET, V62, P639 KEAR BH, 1970, METALL T, V1, P2477 KEAR BH, 1974, ORDER DISORDER TRANS, P440 KHAN T, 1986, MATER SCI TECH SER, V2, P486 LEVERANT GR, 1970, METALL T, V1, P491 LEVERANT GR, 1973, METALL T, V4, P355 MACKAY RA, 1982, METALL TRANS A, V13, P1747 MINER RV, 1986, METALL TRANS A, V17, P491 NATHAL MV, 1989, METALL TRANS A, V20, P133 OHNO N, 1994, JSME INT J A-MECH M, V37, P129 POLLOCK TM, 1992, ACTA METALL MATER, V40, P1 SAKAKI T, 1990, CREEP FRACTURE ENG M, P313 SASS V, 1996, ACTA MATER, V44, P1967 SOCRATE S, 1993, ACTA METALL MATER, V41, P2185 VOLKL R, 1994, SCRIPTA METALL MATER, V31, P1481 WEERTMAN J, 1992, ELEMENTARY DISLOCATI, P107 NR 28 TC 0 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI, 980, JAPAN SN 0021-4876 J9 J JPN INST METAL JI J. Jpn. Inst. Met. PD MAY PY 1999 VL 63 IS 5 BP 641 EP 648 PG 8 SC Metallurgy & Metallurgical Engineering GA 205KR UT ISI:000080820400021 ER PT J AU Page, RA Leverant, GR TI Inhibition of interdiffusion from MCrAlY overlay coatings by application of a Ni-Re interlayer SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID RHENIUM ADDITIONS; BASE SUPERALLOY AB The durability of protective coatings on combustion turbine blades and vanes is a critical issue in the power generation industry. Coating life usually dictates the refurbishment intervals for these components, and these intervals have generally been of shelter duration than desired by the operators of the equipment. Both MCrAlY and aluminide type coatings protect against oxidation and hot corrosion by forming a protective Al2O3 surface layer. Degradation of the coatings occurs by depletion of the aluminum content of the coating through interdiffusion with the substrate and through the formation and spallation of an external Al2O3 scale. The results obtained in this study clearly show that the application of a thin interlayer of Ni-Re beneath the MCrAlY coating can significantly decrease the growth rate of the inner beta-NiAl depletion zone. Order of magnitude reductions in the inner depletion zone thickness formed at 1000 h were obtained with both the Ni-32 wt.% Re and the Ni-47 wt.% Re interlayer coatings. Since formation of the inner depletion zone is believed to result from interdiffusion with the substrate, these results suggest that the Ni-Re interlayer provided a significant impediment to the inward diffusion of Al into the substrate. C1 SW Res Inst, Mat & Struct Div, San Antonio, TX 78238 USA. RP Page, RA, SW Res Inst, Mat & Struct Div, 6220 Culebra, San Antonio, TX 78238 USA. CR ANTON DL, 1984, SUPERALLOYS, P601 BLAVETTE D, 1986, SCRIPTA METALL, V20, P1395 CHERUVU NS, 1996, JOM-J MIN MET MAT S, V48, P34 GIAMEI AF, 1985, METALL TRANS A, V16, P1997 LAHRMAN DF, 1988, ACTA METALL, V36, P1309 LEVERANT GR, 1976, F4462076C0028 MURAKAMI H, 1994, APPL SURF SCI, V76, P177 NEUBAUER CM, 1994, SCRIPTA METALL MATER, V31, P99 SRINIVASAN V, 1995, MATER MANUF PROCESS, V10, P955 NR 9 TC 7 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1999 VL 121 IS 2 BP 313 EP 319 PG 7 SC Engineering, Mechanical GA 189BB UT ISI:000079883300019 ER PT J AU Kopylov, AA Paleeva, SY Styazhkin, VA Veksler, YG Paderov, AN TI The effect of temperature and vibration on the properties of nitride-coated compressor blades for gas turbine engines SO PROTECTION OF METALS LA English DT Article AB The dependences "wear resistance vs. temperature" of the compositions (sic)961 + (Ti, Zr)N and BT8 + (Ti, Zr)N were measured and the service life limit of the materials was estimated. The effects of free-vibrational amplitude and preliminary tempering temperature on residual wear resistance, corrosion fatigue, and yield strength were determined. Some essential differences in behavior between the steel and coated titanium blades were revealed. C1 Ural State Tech Univ, Ekaterinburg 620002, Russia. RP Kopylov, AA, Ural State Tech Univ, Ul Mira 19, Ekaterinburg 620002, Russia. CR IVANOV EG, 1983, ANTIFRIKTSIONNYE POK, P149 PADEROV AN, 1997, ZAVODSK LAB, V63, P55 VEKSLER YG, 1998, ZASHCH MET, V34, P288 NR 3 TC 0 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O PLENUM/CONSULTANTS BUREAU 233 SPRING ST, NEW YORK, NY 10013 USA SN 0033-1732 J9 PROT MET-ENGL TR JI Protect. Met. PD MAR-APR PY 1999 VL 35 IS 2 BP 195 EP 197 PG 3 SC Metallurgy & Metallurgical Engineering GA 186AP UT ISI:000079704500020 ER PT J AU Kruzic, JJ Campbell, JP Ritchie, RO TI On the fatigue behavior of gamma-based titanium aluminides: Role of small cracks SO ACTA MATERIALIA LA English DT Article ID HIGH-CYCLE FATIGUE; GROWTH-BEHAVIOR; TIAL-ALLOY; PROPAGATION; FRACTURE AB Gamma-TiAl based alloys have recently received attention for potential elevated temperature applications in gas-turbine engines. However, although expected critical crack sizes for some targeted applications (e.g. gas-turbine engine blades) may be less than similar to 500 mu m, most fatigue-crack growth studies to date have focused on the behavior of large (on the order of a few millimeters) through-thickness cracks. Since successful implementation of damage-tolerant life-prediction methodologies requires that the fatigue properties be understood for crack sizes representative of those seen in service conditions, the present work is focused on characterizing the initiation and growth behavior of small (a similar to 25-300 mu m) fatigue cracks in a y-TiAl based alloy, of composition Ti-47Al-2Nb-2Cr-0.2B (at.%), with both duplex (average grain size of similar to 17 mu m) and refined lamellar (average colony size of similar to 145 mu m) microstructures. Results are compared to the behavior of large (a > 5 mm), through-thickness cracks from a previous study. Superior crack initiation resistance is observed in the duplex microstructure, with no cracks nucleating after up to 500 000 cycles at maximum stress levels (R = 0.1) in excess of the monotonic yield stress, sigma(y). Comparatively, in the lamellar microstructure cracks nucleated readily at applied maximum stresses below the yield stress (85% sigma(y)) after as few as 500 cycles. In terms of crack growth, measurements for small fatigue cracks in the duplex and lamellar microstructures showed that both microstructures have comparable intrinsic fatigue-crack growth resistance in the presence of small flaws. This observation contrasts previous comparisons of large-crack data, where the lamellar structure showed far superior fatigue-crack growth resistance than the duplex structure. Such "small-crack effects" are examined both in terms of similitude (i.e. crack tip shielding) and continuum (i.e. biased microstructural sampling) limitations of traditional linear elastic fracture mechanics. (C) Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Ritchie, RO, Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. CR BADRINARAYANAN K, 1996, METALL MATER TRANS A, V27, P3781 BALSONE SJ, 1995, MAT SCI ENG A-STRUCT, V192, P457 BLOYER DR, 1998, METALL MAT T A, V30 BOWEN P, 1995, MAT SCI ENG A-STRUCT, V192, P443 CAMPBELL JP, 1996, DEFORMATION FRACTURE, V4, P141 CAMPBELL JP, 1997, MAT SCI ENG A-STRUCT, V239, P722 CAMPBELL JP, 1997, SCRIPTA MATER, V37, P707 CAMPBELL JP, 1998, METALL MAT T A, V30 CHAN KS, 1992, METALL T A, V23, P1663 CHAN KS, 1993, METALL TRANS A, V24, P113 CHAN KS, 1993, METALL TRANS A, V24, P569 CHAN KS, 1993, STRUCTURAL INTERMETA, P223 CHAN KS, 1997, METALL MATER TRANS A, V28, P79 CHAN KS, 1998, METALL MATER TRANS A, V29, P73 COWLES BA, 1996, INT J FRACTURE, V80, P147 DAVIDSON DL, 1993, METALL TRANS A, V24, P1555 GNANAMOORTHY R, 1995, SCRIPTA METALL MATER, V33, P907 HARRISON GF, 1996, NATO ASI SER, P309 KIM JK, 1994, MAG CONCRETE RES, V46, P7 KIM YW, 1991, JOM, V43, P40 KIM YW, 1995, MAT SCI ENG A-STRUCT, V192, P519 KUMPFERT J, 1995, MAT SCI ENG A-STRUCT, V192, P465 LARSEN JM, 1995, GAMMA TITANIUM ALUMI, P821 LIU CT, 1995, GAMMA TITANIUM ALUMI, P679 MAHMOUD MA, 1988, ENG FRACT MECH, V31, P357 MAHMOUD MA, 1992, ENG FRACT MECH, V41, P961 NEWMAN JC, 1981, ENG FRACT MECH, V15, P185 NICHOLAS T, 1996, INT J FRACTURE, V80, P219 RAO KTV, 1995, MAT SCI ENG A-STRUCT, V192, P474 RITCHIE RO, 1986, MATER SCI ENG, V84, P11 RITCHIE RO, 1986, SMALL FATIGUE CRACKS, P167 RITCHIE RO, 1989, ENG FRACT MECH, V32, P361 SURESH S, 1984, INT MET REV, V29, P445 WISSUCHEK DJ, 1995, GAMMA TITANIUM ALUMI, P875 NR 34 TC 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD FEB 5 PY 1999 VL 47 IS 3 BP 801 EP 816 PG 16 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 170BQ UT ISI:000078785900008 ER PT J AU Mann, BS TI Solid-particle erosion and protective layers for steam turbine blading SO WEAR LA English DT Article DE steam turbine blading; erosive wear; boronising; boundary layer ID COATINGS AB Solid particle erosion of steam path surfaces is a major concern in steam turbines. This is mainly due to the formation of magnetite on the inside of boiler tubes. This builds up, spalls and travels along with the steam causing erosion in areas where steam velocities are the highest. The steam velocities are the highest in the high pressure sections of steam turbines. The erosion depends upon the base material and steam flow conditions. The base material is generally protected by plasma/detonation sprayed and thermo-chemically formed diffusion coatings. In this paper prevention and visualisation of erosive wear of two dimensional steam turbine 12Cr steel blading under similar Reynolds number to that of steam turbines is described. For erosion visualisation, a rotating disc apparatus has been used. From the study, it was observed that erosion of complicated steam turbine blading depends upon the flow conditions especially now separation, reattachment and boundary layer growth. The flow visualisation was obtained from the replicas which were etched on the aluminium disc due to erosive wear. Further, to control the erosive wear of steam turbine blading, these were given a hard diffusion layers based upon boronising. The performance of these hard diffused layers along with erosion visualisation of 12Cr steam turbine blading are reported in this paper. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Bharat Heavy Elect, Corp Res & Dev, Mat Sci Lab, Hyderabad 500093, Andhra Pradesh, India. RP Mann, BS, Bharat Heavy Elect, Corp Res & Dev, Mat Sci Lab, Hyderabad 500093, Andhra Pradesh, India. CR BUCHANAN ER, 1987, TURBOMACHINERY I JAN, P25 KAWAGISHI H, 1990, ADV STEAM TURBINE TE, P23 KRZYANOWSKI JA, 1994, J ENG GAS TURB POWER, V116, P442 LAMARRE L, 1990, EPRI J OCT, P30 MANN BS, 1994, 1 INT S TURB HEAT MA MANN BS, 1997, 2 INT S TURB HEAT MA MANN BS, 1997, WEAR, V208, P125 MANN BS, 1998, WEAR, V217, P56 ORTOLANO RJ, 1983, TURBOMACHINERY I MAY, P56 SHANOV V, 1996, TRANSPORT PHENOMENON, P227 SIELSKI DR, 1997, SERMATCH REV, V57, P1 SUSAN WB, 1991, DESIGN REPAIR REFURB, P177 TABAKOFF W, 1995, J ENG GAS TURB POWER, V117, P146 WAHL G, 1975, VDI Z, V117, P785 WALSH PN, 1995, J ENG GAS TURB POWER, V117, P152 NR 15 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JAN PY 1999 VL 224 IS 1 BP 8 EP 12 PG 5 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 168JK UT ISI:000078688300002 ER PT J AU Ford, DA Fullagar, KPL Bhangu, HK Thomas, MC Burkholder, PS Korinko, PS Harris, K Wahl, JB TI Improved performance rhenium containing single crystal alloy turbine blades utilizing PPM levels of the highly reactive elements lanthanum and yttrium SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB Turbine inlet temperatures have now approached 1650 degrees C (3000 degrees F) at maximum power for the latest large commercial turbofan engines, resulting in high file efficiency and thrust levels approaching or exceeding 445 kN (100,000 lbs.). High reliability and durability must be intrinsically designed into these turbine engines to meet operating economic targets and ETOPS certification requirements. This level of performance has been brought about by a combination of advances in air cooling for turbine blades and vanes, computerized design technology for stresses and airflow: and the development and application of rhenium (Rc) containing, high gamma' volume fraction nickel-base single crystal superalloys, with advanced coatings, including prime-reliant ceramic thermal barrier coatings (TBCs). Re additions to cast airfoil superalloys not only improve creep and thermomechanical fatigue strength but also environmental properties, including coating performance. Re slows down diffusion in these alloys at high operating temperatures [1]. At high gas temperatures, several issues are critical to turbine engine performance retention, blade life, and integrity. These are tip oxidation in particular for shroudless blades, internal oxidation for lightly cooled turbine blades, and TBC adherence to both the airfoil and tip seal liner. It is now known that sulfur (S) at levels <10 ppm but >0.2 ppm in these alloys reduces the adherence of ct alumina protective scales on these materials or their coatings by weakening the Van der Waal's bond between the scale and the alloy substrate. A team approach has been used to develop an improvement to CMSX-4(1) alloy which contains 3 percent Re, by reducing 3 and phosphorus (P) levels in the alloy to <2 ppm, combined with residual additions of lanthanum (La) + yttrium (Y) in the range 10-30 ppm. Results from cyclic, burner rig dynamic oxidation testing at 1093 degrees C (2000 degrees F) show thirteen times the number of cycles to initial alumina scale spallation for CMSX-4 [La + Y] compared to standard CMSX-4. A key factor for application acceptance is of course manufacturing cost. The development of improved low reactivity prime coats for the blade shell molds along with a viable, tight dimensional control yttrium oxide core body are discussed. The target is to attain grain yields of single crystal CMSX-4 (ULS) (La + Y) turbine blades and casting cleanliness approaching standard CMSX-4. The low residual levels of La + Y along with a sophisticated homogenisation/solutioning heat treatment procedure result in full solutioning with essentially no residual gamma/gamma' eutectic phase, Ni (La, Y) low melting point eutectics, and associated incipient Inciting pores. Thus, full CMSX-4 mechanical properties are attained The La assists with ppm chemistry control of the Y throughout the single crystal turbine blade castings through the formation of a continuous lanthanum oxide film between the molten and solidifying alloy and the ceramic core and prime coat of the shell mold. Y and La tie up the <2 ppm brit >0.2 ppm residual S in the alloy as very stable Y and Ln sulfides and oxysulfides, thus preventing diffusion of the S atoms to the alumina scale layer under high temperature, cyclic oxidising conditions. La also forms a stable phosphide. CMSX-4 (ULS) (La + Y) HP shroudless turbine blades will commence Engine testing in May 1998. C1 Rolls Royce PLC, CRDF, Bristol BS12 7QE, Avon, England. Rolls Royce PLC, Allison Engine Co, Indianapolis, IN USA. Cannon Muskegon Corp, SPS Technol Inc, Muskegon, MI USA. RP Ford, DA, Rolls Royce PLC, CRDF, Postal Code GP1-6,POB 3,Gypsy Patch Lane, Bristol BS12 7QE, Avon, England. CR 9714135, GB, APPL *BUTT LTD, 1972, SMITH MET REF BOOK AIMONE PR, 8 INT S SUP BREN, BRENTNALL WD BROOMFIELD RW, 1997, ASME TURB EXP 97 2 5 GOLDSHMIDT D, 1992, SUPERALLOYS, P775 GSCHNEIDER KA, 1973, THERMOCHEMISTRY RARE GSCHNEIDER KA, 1992, THERMOCHEMISTRY RARE HONDROS FD, 1989, MAGIC ACTIVE ELEMENT, V11 KORINKO PS, 1996, ASME TURB EXP 96 JUN MCVAY RT, SUPERALLOYS, P807 MICKLE TH, 1994, AER 94 ASM INT JUN 6 SMEGGIL JG, 1985, METALL T A, V16, P1164 SMEGGIL JG, 1986, METALL TRANS A, V17, P923 SMIALEK JL, 1996, 8 INT S SUP MIN MET THOMAS MC, 1994, COST 501 C MAT ADV E NR 16 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1999 VL 121 IS 1 BP 138 EP 143 PG 6 SC Engineering, Mechanical GA 166TC UT ISI:000078592400021 ER PT J AU Fuglsang, P Madsen, HA TI Optimization method for wind turbine rotors SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article DE aerodynamics; horizontal axis turbines; power generation; rotors; turbine blades; wind; optimization; fatigue AB This paper presents a recently developed numerical multi-disciplinary optimization method for design of horizontal axis wind turbines. The method allows multiple constraints. The objective was minimum cost of energy, determined by the design giving fatigue and extreme loads and the annual production of energy. Time domain aeroelastic calculations and Rainflow counting provided the life time equivalent fatigue loads. A semi-empirical approach was developed for their sensitivities. This resulted in substantial savings in computing time. An optimization of a 1.5 MW stall regulated rotor demonstrated the design method, and the results showed that constraints on loads are important for the applicability of the optimization results. Shape optimization of the rotor resulted in maximum strain on more than 80% of the blade span and hence more efficient use of material. The cost of energy was reduced compared to a traditional design with the same swept area. The optimum specific power was found to 460 W/m(2), which is lower than that of modern Danish wind turbines. Studies for optimum airfoil characteristics showed that the airfoil sections should have a relative high maximum lift at the entire span including the tip region. An increase in the swept area should therefore involve a complete redesign of the rotor blades, and avoid the use of low maximum lift airfoils at the tip, which so far has been widely used to control peak power. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Riso Natl Lab, DK-4000 Roskilde, Denmark. RP Fuglsang, P, Riso Natl Lab, DK-4000 Roskilde, Denmark. CR BAKKER D, 1994, 94IEC88DBA076 IEC CE BROOKS TF, 1989, AIRFOIL SELF NOISE P FLEURY C, 1986, INT J NUMER METH ENG, V23, P409 FUGLSANG P, 1995, P 14 ASME WIND EN S, P151 FUGLSANG P, 1995, RISOR799EN RIS NAT L GLAUERT H, 1963, AIRPLANE PROPELLERS GRABAU P, 1995, LM 29 2 DEV 28 M BLA HENDRIKS B, 1996, P EUWEC 96 EUR UN WI HOADLEY D, 1993, AEROFOIL SECTION DES LOWSON MV, 1994, W130031REP ETSU OYE S, 1992, FLEX4 COMPUTER CODE RASMUSSEN F, 1994, P WINDPOWER 92, P347 SELIG MS, 1995, P 14 ASME WIND EN S, P13 TANGLER J, 1987, P WINDPOWER 87, P99 THOMSEN K, 1992, RISOR653EN RIS NAT L VANDERPLAATS GN, 1973, COMPUT STRUCT, V3, P739 NR 16 TC 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AERODYN JI J. Wind Eng. Ind. Aerodyn. PD MAR PY 1999 VL 80 IS 1-2 BP 191 EP 206 PG 16 SC Engineering, Civil; Mechanics GA 160FP UT ISI:000078220000011 ER PT J AU Mann, BS TI Particle erosion - a new concept of flow visualization and boundary layer investigations of rotating machines at high Reynolds numbers SO WEAR LA English DT Article DE rotating disc; wear mapping; boundary layer; flow separation ID COATINGS; PROTECTION; CASCADE; WEAR AB Erosive wear due to solid particles is an undesirable phenomenon. It causes structural failure directly or in combination with fatigue or corrosion. This generally is more serious in rotating machinery of all types mainly the blades of hydro, steam and gas turbines. However, there are positive aspects of this unwanted phenomenon, which in this paper, are utilized for investigation of boundary layer growth, separation and reattachment of separated now. In the present investigation, flow visualization of two-dimensional objects viz., circular, aerofoil and hydrofoil based on above concept has been described. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Bharat Heavy Elect, Div Res & Dev, Hyderabad 500093, Andhra Pradesh, India. RP Mann, BS, Bharat Heavy Elect, Div Res & Dev, Hyderabad 500093, Andhra Pradesh, India. CR ADLER WF, 1977, ASTM STP, V664 ALEXIEFF PW, 1979, COMBUSTION, V7, P12 DEUTSCH S, 1987, J TURBOMACH, V109, P520 DEUTSCH S, 1988, ASME, V110, P138 DEUTSCH S, 1988, ASME, V110, P146 FISHER TE, 1989, J AM CERAM SOC, V72, P252 HASHISH M, 1994, J TRIBOL-T ASME, V116, P439 IWAI Y, 1997, WEAR, V210, P211 KAWAGISHI K, 1990, ADV STEAM TURBINE TE, P23 KHALIL YF, 1996, WEAR, V201, P64 MANN BS, 1994, INT S TURB HEAT MASS MANN BS, 1998, WEAR, V217, P56 MEE DJ, 1992, J TURBOMACH, V114, P163 SCHLICHTING H, 1968, BOUNDARY LAYER THEOR SHANOV V, 1996, ASME, V240, P227 TABAKOFF W, 1995, J ENG GAS TURB POWER, V117, P146 WALSH PN, 1995, J ENG GAS TURB POWER, V117, P152 WANG BQ, 1996, WEAR, V199, P24 NR 18 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD DEC PY 1998 VL 223 IS 1-2 BP 110 EP 118 PG 9 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 149TJ UT ISI:000077621400014 ER PT J AU Bond, IP Ansell, MP TI Fatigue properties of jointed wood composites part I - Statistical analysis, fatigue master curves and constant life diagrams SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB The primary aim of this work was to assess the fatigue performance of scarf-jointed laminated wood composites used to manufacture wind turbine blades and establish simple fatigue design procedures. Laminates made from poplar (Populus canadensis/serotina), Khaya (Khaya ivorensis) and beech (Fagus sylvatica), incorporating typical scarf joints, were assessed under reversed loading (R=-1). Scarf joints were found to be great equalizers of fatigue performance for wood species with different static strengths. Poplar was investigated at several other R ratios ( +3, -3, -0.84 and 0.33). The application of 95% survival probability limits derived from pooled data increases the statistical reliability of sigma-N curves and gives an improved estimate of a material's minimum performance. The sigma-N curves derived for all th ree wood species at R=-1 were normalized with respect to ultimate compressive strength values and found to be practically coincidental. This allowed the derivation of a master curve for a generic scarf-jointed wood laminate under reversed load conditions. This relationship was verified using data from the literature and found to be a good predictor of fatigue performance. The construction of simple triangulated constant life diagrams based on static tensile and compressive tests and fatigue testing at R=-1 brings about a rapid assessment of the overall fatigue performance of any wood composite. These can then be used in the fatigue design or life prediction of wood composites under cyclic loading. (C) 1998 Kluwer Academic Publishers. C1 Univ Bristol, Dept Aerosp Engn, Bristol BS8 1TR, Avon, England. Univ Bath, Sch Mat Sci, Bath BA2 7AY, Avon, England. RP Bond, IP, Univ Bristol, Dept Aerosp Engn, Bristol BS8 1TR, Avon, England. CR *ASTM, 1972, ASTM E, V206 ANSELL MP, 1991, P INT TIMB ENG C TRA, V4, P194 ANSELL MP, 1993, P 9 INT C COMP MAT, V5, P692 BARNARD PM, 1988, INT J FATIGUE, V10, P171 BODIG J, 1982, MECH WOOD WOOD COMPO BOHANNAN W, 1969, FPL114 USDA US FOR P BONFIELD PW, 1988, P 10 BWEA WIND EN C, P377 BONFIELD PW, 1989, P EUR WIND EN C EWEC, P406 BONFIELD PW, 1991, J MATER SCI, V26, P4765 BONFIELD PW, 1991, P 13 BWEA WIND EN C, P311 BONFIELD PW, 1991, THESIS U BATH BONFIELD PW, 1992, P 14 BWEA WIND EN C, P243 CHOU PC, 1978, J COMPOS MATER, V12, P177 CURTIS PT, 1989, J STRAIN ANAL ENG, V24, P235 DESCH HE, 1981, TIMBER ITS STRUCTURE DIETZ AGH, 1943, T ASME, P187 DINWOODIE JM, 1981, TIMBER ITS NATURE BE FULLER FB, 1943, J AERONAUT SCI MAR, P81 HANCOCK M, 1994, WEGR0386201 DTI HANCOCK M, 1995, P 17 BWEA WIND EN C, P275 IBUKI Y, 1962, J JAPAN SOC TESTING, V11, P103 IMAYAMA N, 1970, MOKUZAI GAKKAISHI, V16, P319 JENKINS G, 1962, 17176B3040 STRUCT MA JOHNSON PE, 1985, DOENASA02861 JOHNSON PE, 1985, NASACR174910 JOHNSON PE, 1985, UDRTR8545 KOMMERS WJ, 1943, 1327 USDA US FOR PRO KYANKA GH, 1980, INT J FRACTURE, V16, P609 LEWIS WC, 1946, P ASTM, V46, P814 LEWIS WC, 1951, P US FOREST PROD RES, V5, P221 LEWIS WC, 1962, 2236 USDA US FOR PRO MINER MA, 1945, T ASME, V67, A159 NATRELLA MG, 1963, EXPT STAT HDB, V91 OTA M, 1966, J JPN WOOD RES SOC, V12, P26 POPPEN M, 1991, ECNRX91077 NETH EN R SEKHAR AC, 1963, J NAT BLDG ORG, V8, P36 SPERA DA, 1991, NASA REFERENCE PUBLI, V1236 STERR R, 1963, HOLZ ROH WERKST, V21, P47 TSAI KT, 1984, P 6 BWEA WIND EN C W, P239 TSAI KT, 1990, J MATER SCI, V25, P865 NR 40 TC 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN 1 PY 1998 VL 33 IS 11 BP 2751 EP 2762 PG 12 SC Materials Science, Multidisciplinary GA 149DU UT ISI:000077590500004 ER PT J AU Wolfe, D Singh, J TI Functionally gradient ceramic/metallic coatings for gas turbine components by high-energy beams for high-temperature applications SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THERMAL BARRIER COATINGS; PHASE-COMPOSITION; MICROSTRUCTURES; DEPOSITION AB Failure of turbine blades generally results from high-temperature oxidation, corrosion, erosion, or combinations of these procedures at the tip, and the leading and trailing edges of a turbine blade. To overcome these limitations, functionally gradient ceramic/metallic coatings have been produced by high-energy beams for high-temperature applications in the aerospace and turbine industries to increase the life of turbine components. Thermal spray processes have long been used to apply high-temperature thermal barrier coatings to improve the life of turbine components. However, these processes have not met the increased demand by the aerospace and turbine industries to obtain higher engine temperatures and increased life enhancement as a result of the inhomogeneous microstructure, unmelted particles, voids, and poor bonding with the substrate. High-energy beams, i.e. electron beam-physical vapour deposition (EB-PVD), laser glazing, laser surface alloying, and laser surface cladding, have been explored to enhance the life of turbine components and overcome the limitations of the thermal spray processes. EB-PVD has overcome some of the disadvantages of the thermal spray processes a nd has increased the life of turbine components by a factor of two as a result of the columnar microstructure in the thermal barrier coating (TBC). Laser glazing has been used to produce metastable phases, amorphous material, and a fine-grained microstructure, resulting in improved surface properties such as fatigue, wear, a nd corrosion resistance at elevated temperatures without changing the composition of the surface material. Laser surface alloying and laser surface cladding have shown promising results in improving the chemical, physical, and mechanical properties of the substrate's surface. Metal-matrix composite coatings have also been produced by a laser technique which resulted in increased wear- and oxidation-resistant properties. The advantages and disadvantages of thermal spray processes, EB-PVD, laser glazing, laser surface alloying, and laser surface cladding will be discussed. Microstructural evolution of thermal barrier coatings, recent advancements in functionally gradient coatings, laser grooving, and multilayered textured coatings will also be discussed. (C) 1998 Kluwer Academic Publishers. C1 Penn State Univ, Appl Res Lab, University Pk, PA 16904 USA. RP Wolfe, D, Penn State Univ, Appl Res Lab, University Pk, PA 16904 USA. EM dew125@psu.edu jxs46@psu.edu CR AITA CR, 1994, JOM-J MIN MET MAT S, V46, P40 APPIANO S, 1993, J MATER SYNTH PROC, V1, P17 BERNDT CC, 1984, THIN SOLID FILMS, V119, P173 BUNSHAH R, 1994, HDB DEPOSITION TECHN FAUCHAIS P, 1991, MAT SCI MONOGR, V67, P3 FOUJANET M, 1988, ZIRCONIA 88 ADV ZIRC, P89 GELL M, 1994, JOM-J MIN MET MAT S, V46, P30 GILMAN PS, 1993, JOM-J MIN MET MAT S, V45, P41 HARMSWORTH PD, 1991, J MATER SCI, V26, P3991 HARMSWORTH PD, 1992, J MATER SCI, V27, P611 HARMSWORTH PD, 1992, J MATER SCI, V27, P616 HERMAN H, 1988, SCI AM, V259, P112 HOCKING M, 1989, METALLIC CERAMIC COA INGO GM, 1990, SURF INTERFACE ANAL, V16, P515 KINGERY W, 1976, INTRO CERAMICS KLEER G, 1991, HIGH PERFORMANCE CER, P329 LEE EY, 1991, HIGH PERFORMANCE CER, P292 LELAIT L, 1989, MAT SCI ENG A-STRUCT, V121, P475 LIDE D, 1990, HDB CHEM PHYSICS LYNCH C, 1989, PRACTICAL HDB MAT SC MCDONALD G, 1980, THIN SOLID FILMS, V73, P491 MEIER S, 1991, J MET, V43, P51 MILLER RA, 1989, J ENG GAS TURB POWER, V111, P301 SCHNEIDER S, 1991, ENG MAT HDB CERAMICS, V4, P30 SHACKELFORE J, 1994, CRC MAT SCI ENG HDB SHANKAR NR, 1984, THIN SOLID FILMS, V119, P159 SINGH J, 1987, ACTA METALL, V35, P1987 SINGH J, 1987, HIGH TEMP TECHNOL, V5, P131 SINGH J, 1988, METALL T, V8, P1588 SINGH J, 1992, J MET, V9, P8 SINGH J, 1994, J MATER SCI, V29, P5232 SINGH J, 1996, SURF COAT TECH, V79, P35 SMITH RW, 1995, JOM-J MIN MET MAT S, V47, P32 STECURA S, 1980, NASA TECH BRIEFS, V5, P321 STECURA S, 1982, CERAM B, V61, P256 UNAL O, 1994, J AM CERAM SOC, V77, P984 VINCENZINI P, 1990, IND CERAM, V10, P113 WOLFE D, 1995, P 1995 INT EL BEAM C, P135 WOLFE DE, 1997, ADV COATINGS TECHNOL, P93 WORTMAN DJ, 1990, J ENG GAS TURB POWER, V112, P527 WU BC, 1989, J AM CERAM SOC, V72, P212 WU BC, 1990, MAT SCI ENG A-STRUCT, V124, P215 YONUSHONIS TM, 1992, AM CERAM SOC BULL, V71, P1191 NR 43 TC 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 15 PY 1998 VL 33 IS 14 BP 3677 EP 3692 PG 16 SC Materials Science, Multidisciplinary GA 149DY UT ISI:000077590900025 ER PT J AU Szolwinski, MP Farris, TN TI Observation, analysis and prediction of fretting fatigue in 2024-T351 aluminum alloy SO WEAR LA English DT Article DE fretting; microslip; friction fatigue ID MECHANICS; INITIATION AB Fretting is associated with microslip at the interface of contacts experiencing oscillatory lends. One consequence of fretting is the formation and subsequent growth of cracks at the edge of contact, a phenomenon known as fretting fatigue. Fretting fatigue is an important fatigue failure mechanism in aircraft structural lap joints and turbine blade/disk contacts. A well-characterized, integrated fretting test system has been developed in which both normal and cyclic tangential fretting loads are applied and monitored in conjunction with a bulk load on the specimen. The experimental data includes histories of the three applied forces and a detailed record of the evolution of interfacial friction coefficient, an evolution driven by surface microslip. The experimental system has been exercised to observe fretting crack nucleation and growth under a wide range of loading conditions in the context of a statistically-designed test matrix. An extensive multiaxial fatigue analysis based on the stress-strain cycle experienced by each point of the bodies subjected to the fretting loads reveals that the critical location for crack formation is the trailing edge of contact, consistent with observations made in the laboratory. The resulting stress-strain cycles are coupled with strain-life theory and literature values of uniaxial fatigue constants to predict fretting fatigue crack nucleation. The data collected for 2024-T351 aluminum alloy correlates very well with this prediction. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. RP Szolwinski, MP, Rensselaer Polytech Inst, Dept Mech Engn Aeronaut Engn & Mech, Jonsson Engn Ctr 2046, 110 8th St, Troy, NY 12180 USA. CR *AM SOC MET, 1985, MET HDB ASM MET HDB *DEF PRINT SERV DE, 1994, MILHDBK5G DEF PRINT, V1 ATTIA MH, 1992, ASTM STP, V1159, P263 BANNANTINE JA, 1990, FUNDAMENTALS METAL F BLATT PA, 1990, THESIS PURDUE U W LA BRAUN AA, 1994, ASTM STP, V1231, P5 BURTON RA, 1965, J BASIC ENG, V87, P177 DHARMAVASAN S, 1994, ASTM STP, V1231, P52 DOBROMIRSKI JM, 1992, ASTM STP, V1159, P60 ENDO K, 1974, B JSME, V17, P647 FOUVRY S, 1996, WEAR, V195, P21 FUCHS HO, 1980, METAL FATIGUE ENG GALLAGHER J, 1983, DAMAGE TOLERANT DESI, V3 HARISH G, 1998, AIAA J, V36, P1087 HILLS DA, 1988, INTERFACE DYNAMICS, P129 HILLS DA, 1994, WEAR, V175, P107 HOEPPNER DW, 1996, DOTFAAAR9610 MCKEIGHAN PC, 1990, ASTM STP, V1092, P52 MCVEIGH PA, 1997, J TRIBOL-T ASME, V119, P797 MONTGOMERY DC, 1997, DESIGN ANAL EXPT MULLER RPG, 1995, THESIS DELFT U TECHN NAKAZAWA K, 1992, ASTM STP, V1159, P115 NISHIOKA K, 1968, B JSME, V11, P437 NOWELL D, 1987, INT J MECH SCI, V29, P355 NOWELL D, 1990, WEAR, V136, P329 PIASCIK RS, 1997, NASATP97206257 LANGL SOCIE D, 1987, J ENG MATER-T ASME, V109, P292 SOCIE D, 1993, ASTM STP, V1191, P7 SZOLWINSKI MP, 1996, WEAR, V198, P93 SZOLWINSKI MP, 1998, THESIS PURDUE U VAN KD, 1985, BIAXIAL MULTIAXIAL F, P479 WATERHOUSE RB, 1971, WEAR, V17, P139 WATERHOUSE RB, 1992, ASTM STP, V1159, P13 NR 33 TC 41 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD OCT PY 1998 VL 221 IS 1 BP 24 EP 36 PG 13 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 146VQ UT ISI:000077453200004 ER PT J AU Czech, N Juez-Lorenzo, M Kolarik, V Stamm, W TI Influence of the surface roughness on the oxide scale formation on MCrAlY coatings studied in situ by high temperature X-ray diffraction SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE MCrAlY coatings; oxidation; gas turbine ID OXIDATION; RHENIUM AB In modem stationary gas turbines for electric power generation the life time of the blades is mainly controlled by the oxidation resistance of the coatings. In the case of protective overlay coatings the surfaces are generally shot peened, whereas bond coats for EBPVD thermal barrier coatings need a smooth surface. For a better understanding of the influence of the surface roughness on the oxide scale formation, in situ studies using high temperature X-ray diffraction were performed on an MCrAlYRe coating with 12% Al and 3% Re for the use as overlay and as bond coat. The measurements were performed in air at 950 and 1000 degrees C. The results show differences in the oxide scale formation on the same coating with an as-sprayed and a polished surface. On the as-sprayed surface Cr2O3 and spinels were observed besides alpha-Al2O3 in the initial state whereas on the polished surface a coherent alpha-Al2O3 scale with inclusions of YAlO3 was observed from the beginning. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Fraunhofer Inst Chem Technol, D-76327 Pfinztal, Germany. Siemens AG, Power Generat Grp KWU, Mat Technol, D-45466 Mulheim, Germany. RP Kolarik, V, Fraunhofer Inst Chem Technol, Joseph von Fraunhofer Str 7, D-76327 Pfinztal, Germany. CR CZECH N, 1994, SURF COAT TECH, V68, P17 CZECH N, 1995, SURF COAT TECH, V76, P28 CZECH N, 1997, SURF ENG, V13, P384 CZECH N, 1997, VGB KRAFTWERKSTECHN, V77, P221 GROSS M, 1997, OXID MET, V48, P171 KOLARIK V, 1993, J PHYS IV, V3, P447 KOLARIK V, 1993, MATER SCI FORUM, V133, P563 PETRUS GJ, 1997, J THERM SPRAY TECHN, V6, P29 ROMMERSKIRCHEN I, 1996, WERKST KORROS, V47, P625 SAHOO P, 1995, P 8 NAT THERM SPRAY, P539 STRAWBRIDGE A, 1994, MATER HIGH TEMP, V12, P177 STREIFF R, 1993, J PHYS IV, V3, P17 NR 12 TC 17 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD OCT 10 PY 1998 VL 109 IS 1-3 BP 36 EP 42 PG 7 SC Materials Science, Coatings & Films; Physics, Applied GA 142LY UT ISI:000077203000007 ER PT J AU Miglietti, W Blum, F TI Advantages of fluoride ion cleaning at sub-atmospheric pressure SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE fatigue crack growth; gas-turbine failures; joint failures; thermal fatigue AB The fluoride ion cleaning (FIC) process is used to assist in the successful braze repair of nickel-based superalloy components. This process is especially effective in removing deeply embedded oxides in wide and narrow cracks typically found in aircraft parts such as in combustors and turbine blades and vanes. Where Al and Ti are present in the base metal, the FIC process depletes these elements from the surface, thereby improving the braze flow and repair of the cracked components. The objective of this paper is to highlight the benefits of using the FIC process at sub-atmospheric pressure. To achieve this, firstly entailed designing and producing specimens suitable to study the fatigue crack behaviour of brazed repaired cracks/joints under mechanical and thermal loading. The cracks/joints prior to brazing were either in an unclean form, i.e. had an oxide layer on, or were fluoride ion cleaned at sub-atmospheric pressure. Fatigue crack propagation tests under constant load as well as under constant stress intensity factor range were conducted in order to study fatigue crack growth characteristics in the parent and braze repaired area. In addition, the resistance to thermal cycling was investigated using single-edge wedge specimens containing brazed repaired joints. Two different braze materials were also under investigation. For the unclean crack specimens, abnormally high crack growth rates were obtained from the brazed repaired area as compared to parent Ni-based material; whereas for the fluoride ion cleaned crack specimens, lower crack growth rates were experienced. Similarly for the unclean crack specimens, the thermal fatigue crack initiation life was significantly shorter compared with the fluoride ion cleaned crack specimens. (C) 1998 Published by Elsevier Science. All rights reserved. C1 CSIR, Div Mat Sci & Technol, ZA-0001 Pretoria, South Africa. RP Miglietti, W, CSIR, Div Mat Sci & Technol, POB 395, ZA-0001 Pretoria, South Africa. NR 0 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD JUN PY 1998 VL 5 IS 2 BP 149 EP 169 PG 21 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 123YU UT ISI:000076153900010 ER PT J AU Chan, KS Cheruvu, NS Leverant, GR TI Coating life prediction under cyclic oxidation conditions SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID DEGRADATION AB The hot gas path section components of land based turbines require materials with superior mechanical properties and good hot corrosion and oxidation resistance. These components are generally coated with either a diffusion coating (aluminide or platinum aluminide) or with an overlay coating (MCrAlY) to provide additional hot corrosion and/or oxidation protection. These coatings degrade due to inward and outward diffusion of elements during service. Outward diffusion of aluminum results in formation of a protective oxide layer on the surface. When the protective oxide spalls, aluminum in the coating diffuses out to reform the oxide layer. Accelerated oxidation and failure of coating occur when the Al content in the coating is insufficient to reform a continuous alumina film. This paper describes development of a coating life prediction model that accounts for both oxidation and oxide spallation under thermal mechanical landing as well as diffusion of elements that dictate the end useful life. Cyclic oxidation data for aluminide and platinum aluminide coatings were generated to determine model constants. Applications of this model for predicting cyclic oxidation life of coated materials are demonstrated. Work is underway to develop additional material data and to qualify the model for determining actual blade and vane coating refurbishment intervals. C1 SW Res Inst, EPRI Mat Ctr Combust Turbines, San Antonio, TX 78228 USA. RP Chan, KS, SW Res Inst, EPRI Mat Ctr Combust Turbines, 6220 Culebra Rd,PO Drawer 28510, San Antonio, TX 78228 USA. CR CHAN KS, 1997, METALL MATER TRANS A, V28, P411 LEE EY, 1987, SURF COAT TECH, V32, P19 LOWELL CE, 1991, OXID MET, V36, P81 NESBITT JA, 1984, THIN SOLID FILMS, V119, P281 NESBITT JA, 1989, DIFFUSION ANAL APPL, P307 NESBITT JA, 1989, J ELECTROCHEM SOC, V136, P1518 NESBITT JA, 1993, STRUCTURAL INTERMETA, P601 PROBST HB, 1988, J MET, V40, P18 SHANKAR S, 1985, 4525814, US SMITH JS, 1990, ASME INT GAS TURB AE NR 10 TC 8 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1998 VL 120 IS 3 BP 609 EP 614 PG 6 SC Engineering, Mechanical GA 110QZ UT ISI:000075393000026 ER PT J AU Panovsky, J Carson, SM TI Prediction of turbine blade vibratory response due to upstream vane distress SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB Turbine blades and vanes operate in a hostile environment, which lends to deterioration of these components over time. This paper describes detailed calculations to predict the vibratory response of a high-pressure turbine blade due to the excitation produced by a single distressed upstream vane in a modem turbofan engine. The approach includes detailed computational fluid dynamics (CFD) analysis of the steady flowfield produced by the distressed vane, Fourier decomposition of the flow variables to determine the harmonic content, unsteady CFD analysis to determine the resulting vibratory response of the blade, and crack propagation analysis to determine blade life. Predictions of vibratory stress and threshold crack size are summarized as functions of vane distress level. The results, which indicate that this type of vane distress can indeed he a significant excitation source for the blades, are shown to be in good agreement with engine experience. The method provides, for the first time, a quantitative approach to setting limits for acceptable levels of vane distress in the field. C1 GE Aircraft Engines, Cincinnati, OH 44135 USA. RP Panovsky, J, GE Aircraft Engines, Cincinnati, OH 44135 USA. CR BROEK D, 1974, ELEMENTARY ENG FRACT GILES MB, 1988, CFDLTR881 HALL KC, 1989, AIAA J, V27, P777 HOLMES DG, 1988, 88GT83 ASME HOLMES DG, 1989, 891932CP AIAA HOLMES DG, 1991, P 6 INT S UNST AER A LORENCE CB, 1991, THESIS DUKE U PLATZER MF, 1988, AGARD MANUAL AEROELA, V2 VERICK RK, 1979, VIBRATION ANAL NR 9 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD JUL PY 1998 VL 120 IS 3 BP 515 EP 521 PG 7 SC Engineering, Mechanical GA 110DL UT ISI:000075364800018 ER PT J AU Vazquez, J Silvera, A Arias, F Soria, E TI Fatigue properties of a glass-fibre-reinforced polyester material used in wind turbine blades SO JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN LA English DT Article DE fatigue; GFRP; wind turbine blades; cumulative distribution function AB Glass-fibre-reinforced polyester (GFRP) is a composite commonly used in the manufacture of wind turbine blades. In the present work, one such material has been subject to static and dynamic tests in order to obtain data that can be applied to the design of wind turbine blades and other machine elements. The results of the static tests established a basis for the determination of a set of tension-tension (constant amplitude and sinusoidal load) dynamic tests with the aim of establishing a mathematical model in order to predict life as a function of the load state and calculate the fatigue limit. The multiplicative model (y = ax(b)) for y = log of life and x = transformed stress (a and b are characteristic parameters of the material obtained from data) matches the data quite well. The conclusion is that the GFRP studied has no fatigue limit. The possible decrease of fatigue strength of the material with solar radiation and moisture absorption was also investigated, with a negative result. C1 ETSI Agron, Dept Ingn Rural, Madrid, Spain. Ctr Invest Energet Medioambientales & Tecnol, Madrid, Spain. RP Vazquez, J, ETSI Agron, Dept Ingn Rural, Ciudad Univ, Madrid, Spain. CR ANDERSEN SI, 1988, EUR COMM WIND EN C H, P342 APPEL N, 1988, NEWECS45 BACH PW, EUR COMM WIND EN C L, P180 BACH PW, 1988, EUR COMM WIND EN C, P337 BACH PW, 1991, ECNC91010 NETH RES E BACH PW, 1992, FATIGUE PROPERTIES D, P250 BIJEN J, 1992, MATER STRUCT, V25, P107 BOLLER KH, 1969, ASTM STP, V460, P217 GERHARZ JJ, 1980, ANAL STATE ART, V1, P29 GREENWOOD JH, 1981, 81120R ERA HALPIN JC, 1973, ASTM STP, V521, P5 KAMINSKI BE, 1973, ASTM STP, V521, P181 KENSCHE CW, EUR COMM WIND EN C L, P184 KIM RY, 1993, MAT SCI TECHNOLOGY C, V13, P500 KRAUSE AR, EFFECT ADHESIVE CHEM, P193 MANDELL JF, 1982, DEV REINFORCED PLAST, V2, P67 NELSON W, 1990, ACCELERATED TESTING, P93 ROSATO DV, 1968, ENV EFFECTS POLYM MA, V1 ROSATO DV, 1968, ENV EFFECTS POLYM MA, V2 SORS L, 1971, FATIGUE DESIGNS MACH, P6 WATANABE M, 1979, ASTM STP, V674, P345 NR 21 TC 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS, SUFFOLK, ENGLAND IP32 6BW SN 0309-3247 J9 J STRAIN ANAL ENG DESIGN JI J. Strain Anal. Eng. Des. PD MAY PY 1998 VL 33 IS 3 BP 183 EP 193 PG 11 SC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing GA 108JK UT ISI:000075262600001 ER PT J AU Kolkman, HJ Kool, GA TI Non destructive investigation of the condition of gas turbine blades SO MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK LA English DT Article ID GROWTH AB In order to determine the remaining life of service exposed turbine blades it is necessary to characterize the degeneration of the microstructure of the base metal during service. Since turbine blades of industrial gas turbines are kept in complete stages, non-destructive inspection (NDI) is very attractive. Hence the goal of the investigation reported here was to evaluate a NDI technique able to detect microstructural changes of the base metal. It was found that single-stage replication tin combination with investigation in a Scanning Electron Microscope) is a relatively simple technique that fulfils all requirements. This technique can be used in-situ on uncoated buckets. For coated turbine blades local removal of the coating is necessary to perform base metal replication. C1 Natl Aerosp Lab NLR, Struct & Mat Lab, NL-8300 AD Emmeloord, Netherlands. RP Kolkman, HJ, Natl Aerosp Lab NLR, Struct & Mat Lab, POB 153, NL-8300 AD Emmeloord, Netherlands. CR AURRECOECHEA JM, 1990, P INT C PHOEN AR US, P165 CHERUVU NS, 1996, JOM-J MIN MET MAT S, V48, P34 FOOTNER PK, 1982, J MATER SCI, V17, P2141 KOUL AK, 1988, METALL TRANS A, V19, P2049 KOUL AK, 1993, P ASM 1993 MAT C MAT, P75 LUCCA DA, 1994, ANN CIRP, V43, P43 MCLEAN D, 1984, MET SCI, V18, P249 STEVENS RA, 1980, SESSDR80072 CENTR EL STRINGER J, 1990, P INT C PHOEN AR US, P1 VISWANATHAN R, 1989, DAMAGE MECHANISMS LI, CH9 WILLSON JHM, 1980, REPLICA SHADOWING FR YOSHIOKA Y, 1993, P ASM 1993 MAT C MAT, P53 NR 12 TC 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0933-5137 J9 MATERIALWISS WERKSTOFFTECH JI Materialwiss. Werkstofftech. PD JUL PY 1998 VL 29 IS 7 BP 339 EP 344 PG 6 SC Materials Science, Multidisciplinary GA 102WL UT ISI:000074949000004 ER PT J AU [Anon] TI Life prediction model developed for gas turbine blade coatings SO MATERIALS PERFORMANCE LA English DT News Item NR 0 TC 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORM JI Mater. Perform. PD JUL PY 1998 VL 37 IS 7 BP 44 EP 44 PG 1 SC Materials Science, Characterization & Testing GA ZZ398 UT ISI:000074725400015 ER PT J AU Rosario, DA Viswanathan, R Wells, CH Licina, GJ TI Stress corrosion cracking of steam turbine rotors SO CORROSION LA English DT Article DE environmentally assisted corrosion; industrial applications; nuclear applications; power generation; rotors; steam turbine; steel; stress corrosion cracking AB In the wake of the catastrophic failure of a low-pressure (LP) turbine disk at the Hinkley Point Nuclear Station in 1969, considerable research and development has been devoted to the problem of stress corrosion cracking (SCC) in steam turbine rotors. Principle factors affecting the susceptibility of rotors to SCC have been identified as disk yield strength applied stress level, and surface film/crevice chemistry. Microstructure and cleanliness of the steel have been found to have relatively little effect. Advances in steel making and forging over the last 20 years have provided manufacturers with additional design and material options to mitigate the problem Increases in forging size capabilities of steel companies and the welded construction of rotors now permit designing with integral and partial integral rotors that use materials with lower yield strength (more SCC resistant) as well as eliminating the SCC problem in bores and keyways. However a recent survey of U.S. utilities has shown that SCC in the blade attachment legion of LP rotors is an increasing concern This problem has led to development of repair and refurbishment methods for rim attachments, especially weld buildup of rims with corrosion-resistant alloys. Life prediction of rotors under SCC conditions currently involves estimating crack growth time from assumed defects to critical size. Factors that govern the location and time of crack initiation are not understood adequately. C1 Struct Integr Associates, San Jose, CA 95118 USA. Elect Power Res Inst, Palo Alto, CA 94303 USA. RP Rosario, DA, Struct Integr Associates, 3315 Almaden Expressway, San Jose, CA 95118 USA. CR *ASM, 1986, MET HDB, V11 *EPRI, 1982, NP2429 EPRI, V1 *EPRI, 1985, NP4056 EPRI *EPRI, 1989, NP6444 EPRI, V1 *EPRI, 1991, NP7385 EPRI *EPRI, 1994, EPRI C MARCH 23 25 1 *EPRI, 1995, TR104026 EPRI *US NUCL REG COMM, 1985, 8559 IE US NUCL REG AMOS DR, 1995, P 4 EPRI TURB GEN ND CARDINAL JW, 1991, P EPRI TURB GEN NDE CHANEY CE, 1989, GEOTHERMAL RESOURCES, V13 CHERUVU S, 1993, PRESSURIZED WATER RE, V21 CLARK WG, 1981, ASME IEEE POW GEN C CRANE J, 1996, COMMUNICATION FEB CZAJKOWSKI CJ, 1987, CORROSION 87 HOUST T DAVID W, 1993, PRESSURIZED WATER RE, V21, P83 DENK J, 1996, P C CLEAN STEEL SUP EISELSTEIN LE, 1983, MICROKINETICS STRESS EISELSTEIN LE, 1987, STRESS CORROSION CRA ENDO T, 1993, PRESSURIZED WATER RE, V21 FUENTES K, 1987, 87JPGCPWR15 ASME GALANES GW, 1991, DESIGN REPAIR REFURB, P241 GOODLIN DL, 1995, P 4 EPRI TURB GEN ND HOLDSWORTH SR, 1996, P C CLEAN STEEL SUP IKEDA Y, 1996, P C CLEAN STEEL SUP JONAS O, 1994, TR103738 EPRI KRAMER E, 1994, PRESSURIZED WATER RE, V26, P89 LESSARD D, 1995, P 4 EPRI TURB GEN WO LYLE FF, 1993, 6 INT S ENV DEGR MAT LYLE FF, 1994, CORROSION 96 HOUST T MAGDOWSKI R, 1983, METALL T A, V19, P1583 MANSFIELD FD, 1994, P WELD REP TECHN FOS NOTTINGHAM L, 1994, P 12 INT C NOND EV N, V1 PLUMMER R, 1993, P STEAM COMB TURB BL RAU CA, 1991, P FOSS STEAM TURB DI ROSARIO DA, 1996, LOW PRESSURE ROTOR R SCARLIN RB, 1990, GS6612 EPRI STAEHLE RW, 1977, FCC7704 EPRI STIEBLER TJ, 1994, ADV STEAM TURBINE TE, V26, P143 TANCZYN H, 1963, ASTM STP, V369 TIPTON A, 1991, PRESSURIZED WATER RE, V13, P249 VISWANATHAN R, 1991, P FOSS STEAM TURB DI VISWANATHAN R, 1996, P C CLEAN STEEL SUP YAMADA M, 1996, P C CLEAN STEEL SUP NR 44 TC 8 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD JUL PY 1998 VL 54 IS 7 BP 531 EP 545 PG 15 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA ZZ844 UT ISI:000074773200005 ER PT J AU Mann, BS TI Erosion visualisation and characteristics of a two dimensional diffusion treated martensitic stainless steel hydrofoil SO WEAR LA English DT Article DE hydrofoil; stainless steel martensitic cast and forged; abrasion; boronizing; mechanical properties; boundary layer AB Erosive wear of complicated water pump and hydro turbine blades is a complex problem. This is due mainly to the many variables involved in the erosive wear. These depend upon type of erodant, base material and flow conditions. In this paper, visualisation and prevention of erosive wear on two dimensional forged 12Cr and 13Cr-4Ni cast steel hydrofoils under flow conditions similar to that of hydroturbines and water pumps is described. An experimental study was taken using a rotating disc apparatus. From the study, it was observed that the erosion of complicated hydrofoils depends on the flow conditions, especially dow separation, reattachment and boundary layer growth. The visualisation of wear on the hydrofoils was obtained from the wear replicas which were etched on the aluminium rotating disc. Further, to control the wear of these hydrofoils, these were given a hard diffused layer based on boronizing. The performance of these hard diffused layers along with wear prediction on 12Cr and 13Cr-4Ni steel hydrofoils are reported in this paper. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Bharat Heavy Elect, Res & Dev, R&D Div, Mat Sci Lab, Hyderabad 500593, Andhra Pradesh, India. RP Mann, BS, Bharat Heavy Elect, Res & Dev, R&D Div, Mat Sci Lab, Hyderabad 500593, Andhra Pradesh, India. CR *GW DIPL ING, 1975, VDIZ117, P785 ADLER WF, 1977, ASTM STP, V664 ALEXIEFF PW, 1979, COMBUSTION, V7, P12 GREIN H, 1992, SULZER TECH REV, V1, P19 GYSEL W, 1982, ASTM, P403 IWAI Y, 1997, WEAR, V210, P211 KAWAGISHI K, 1990, ADV STEM TURBINE TEC, V10, P23 KNAPP RT, 1970, CAVITATION KRAUSE M, 1996, WORKSH SILT DAM EQ H, P192 KUPFER R, 1966, SULZER TECH REV, V4, P173 LINDSCHEID H, 1980, SULZER TECH REV, V4, P162 MANN BS, 1994, 1 INT S TURB HEAT MA MANN BS, 1997, 2 INT S TURB HEAT MA MANN BS, 1997, WEAR, V208, P125 NIMHAM IM, 1989, C WEAR MAT, V1, P9 SCHLICHTING H, 1968, BOUNDARY LAYER THEOR SINHA AK, 1991, ASM HDB, V4, P437 STACK MM, 1993, CORROS SCI, V35, P1027 ZHIGAO W, 1986, IAHR S, V84, P1 NR 19 TC 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 15 PY 1998 VL 217 IS 1 BP 56 EP 61 PG 6 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA ZV096 UT ISI:000074268500007 ER PT J AU Veksler, YG Paderov, AN Kopylov, AA Paleeva, SY Kiselev, AI TI A complex assessment of the erosion-corrosion resistance of nitride-coated compressor turbine blades SO PROTECTION OF METALS LA English DT Article AB TiN- and (Ti,Zr)N-coated (sic)-961 steel turbine blades were tested in a specially designed electrically heated test unit for gaseous abrasive-corrosive wear. The relative decrease in the wear resistance of the coatings with an increase in temperature is inversely proportional to the concurrent squared relative decrease in the internal macrostress of the coatings. (Ti,Zr)N coating proves to be more efficient for corrosion and erosion protection. C1 Ural State Technol Inst, Ekaterinburg 620002, Russia. RP Veksler, YG, Ural State Technol Inst, Ul Mira 19, Ekaterinburg 620002, Russia. CR BIRYUKOV VI, 1974, ZAVODSK LAB, P321 BORISOVA AL, 1985, SOVMESTIMOST TUGOPLA IVANOV EG, 1983, ANTIFRIKTSIONNYE POK, P149 ROGERS PM, 1992, SURF ENG, V8, P48 SAMSONOV GV, 1976, TUGOPLAVKIE SOEDINEN VOITOVICH RF, 1968, OKISLENIE TUGOPLAVKI NR 6 TC 0 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O PLENUM/CONSULTANTS BUREAU 233 SPRING ST, NEW YORK, NY 10013 USA SN 0033-1732 J9 PROT MET-ENGL TR JI Protect. Met. PD MAY-JUN PY 1998 VL 34 IS 3 BP 241 EP 244 PG 4 SC Metallurgy & Metallurgical Engineering GA ZU293 UT ISI:000074182200007 ER PT J AU Daleo, JA Wilson, JR TI GTD111 alloy material study SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID CREEP AB Very few property data on this common turbine blade alloy have been published. As longer hours of service are accumulated, maintenance considerations such as developing optimum component life strategies and repair processes become important. The lack of specific material data hampers the effort of users and repair facilities to achieve optimum service from this alloy. This study measured some of the basic mechanical and metallurgical characteristics of this polycrystalline nickel base superalloy. Tensile and short-term creep rupture properties as well as microstructural and fracture characteristics are presented. Both the as-heat-treated and thermally exposed characteristics at two different temperatures are examined. C1 Wilson & Daleo Inc, Ancaster, ON, Canada. RP Daleo, JA, Wilson & Daleo Inc, Ancaster, ON, Canada. CR AEROSPACE STRUCTURAL E139 ASTM *ASTM, E8 ASTM *GE POW SYST, GER3569 GE POW SYST ANTOLOVICH S, 1979, METALLURGICAL T A, V10 CHELLMAN DJ, 1974, ACTA METALL, V22, P577 KOLKMAN HJ, 1987, MATER SCI ENG, V89, P81 LARSON FR, 1952, T ASME, V74, P765 SCHLIKE PW, 1992, ADV MAT PROCESSE APR SIMS CT, 1987, SUPERALLOYS, V2 STEVENS RA, 1979, MATER SCI ENG, V37, P237 WOODFORD DA, 1981, METALLURGICAL T A, V12 NR 12 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1998 VL 120 IS 2 BP 375 EP 382 PG 8 SC Engineering, Mechanical GA ZM040 UT ISI:000073498700020 ER PT J AU Yang, BD Menq, CH TI Characterization of contact kinematics and application to the design of wedge dampers in turbomachinery blading: Part 1 - Stick-slip contact kinematics SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID VIBRATION CONTROL; FORCED RESPONSE; CANTILEVER BEAM; FRICTION; MOTION AB Friction dampers are often used in turbine design to attenuate blade vibration to acceptable levels so as to prolong blades' service life. A wedge damper, also called a self-centering, blade-to-blade damper can provide more design flexibility to meet various needs in different operating conditions when compared with conventional platform dampers. However, direct coupling of the two inclined friction interfaces of the wedge damper often leads to very complex contact kinematics. In Part I of this two-part paper, a dual-interface friction force model is proposed to investigate the coupling contact kinematics. The key issue of the model formulation is to derive analytical criteria for the stick-slip transitions that can be used to precisely simulate the complex stick-slip motion and thus, the induced friction force as well. When considering cyclic loading, the induced periodic friction forces can be obtained to determine the effective stiffness and damping of the interfaces over a cycle of motion. In Part II of this paper; the estimated stiffness and damping are then incorporated with the harmonic balance method to pi-edict the forced response of a blade constrained by wedge dampers. C1 Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. RP Yang, BD, Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. CR ANDERSON JR, 1990, J SOUND VIB, V140, P287 BINDEMANN AC, 1992, FRICTION INDUCED DE, V49 CAMERON TM, 1990, J VIB ACOUST, V112, P175 DENHARTOG JP, 1931, T AM SOC MECH ENG, V53, P107 DOWELL EH, 1983, J SOUND VIB, V91, P255 DOWELL EH, 1983, J SOUND VIB, V91, P269 EARLES SWE, 1972, J SOUND VIBRATION, V24, P445 GOODMAN LE, 1956, J APPL MECH, V23, P421 GRIFFIN JH, 1980, ASME, V102, P329 GRIFFIN JH, 1991, J VIB ACOUST, V113, P225 MENQ CH, 1985, ASME, V107, P19 MENQ CH, 1986, ASME, V108, P300 MENQ CH, 1986, ASME, V108, P50 MENQ CH, 1989, ASME, P71 MENQ CH, 1991, J SOUND VIB, V144, P427 MUSZYNSKA A, 1983, J VIB ACOUST, V105, P434 ODEN JT, 1983, J APPL MECH-T ASME, V50, P67 PFEIFFER F, 1992, PHILOS T ROY SOC A, V338, P503 SANLITURK KY, 1996, J SOUND VIB, V193, P511 SRINIVASAN AV, 1983, J ENG GAS TURB POWER, V105, P332 WAGNER LF, 1990, ASME, V112, P78 YANG BD, 1996, ASME, V119, P472 YANG BD, 1996, THESIS OHIO STATE U YEH GCK, 1966, J ACOUST SOC AM, V39, P14 NR 24 TC 7 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1998 VL 120 IS 2 BP 410 EP 417 PG 8 SC Engineering, Mechanical GA ZM040 UT ISI:000073498700025 ER PT J AU Seth, BB TI Fifty years of metallurgy in steam turbines: Retrospect and prospects SO TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS LA English DT Article AB The drive to produce power at the lowest possible cost has led to major advances in the unit size, efficiency, reliability and maintainability of steam turbines. The development of new materials and processes together with the understanding of their behavior have made these advances a reality. Although Ti, Co and Ni based alloys have been used for isolated applications, steels of various types are the dominant material used in steam turbines. The key improvements in steels include optimized compositions and heat treatments, control of residual elements and better steelmaking and forging practices. These have resulted in greater cleanliness and homogeneity, reduced temper embrittlement, and enhanced toughness, stress corrosion resistance and creep properties. Advanced in-service inspection techniques,life prediction models and weld repair procedures have improved turbine reliability, availability and life. The trend toward more efficient, cost effective units is expected to promote higher temperature, bigger single-shaft units and larger low pressure elements which will present new challenges to metallurgists. Stronger ferritic high-temperature steels of the 9-12% Cr type and titanium alloys for longer last row blades will, be needed. Also, pressure to reduce development cycles and costs will require the use of materials, process, and component behavior modelling. C1 Westinghouse Elect Corp, Div Technol, Power Generat Business Unit, Orlando, FL 32826 USA. RP Seth, BB, Westinghouse Elect Corp, Div Technol, Power Generat Business Unit, Quadrangle,4400 Alafayer Trail, Orlando, FL 32826 USA. CR 1982, SEM STEAM TURB DISC *ASTM, 1968, ASTM STP, V407 *ASTM, 1972, ASTM STP, V499 *EPRI, 1979, EPRI WORKSH TURB ROT *EPRI, 1980, EPRI SEM CRACK LOW P *EPRI, 1983, CS3139 EPRI *EPRI, 1985, SOL PRAT ER STEAM TU *EPRI, 1986, CS4515 EPRI *EPRI, 1988, CSEL5593 EPRI *EPRI, 1989, CS6535 EPRI *EPRI, 1991, P FOSS STEAM TURB DI *EPRI, 1995, EPRI WORKSH CLEAN SU *NAT PHYS LAB, 1989, MTDATA MET THERM DAT AMOS DR, 1995, P 3 INT C PARS TURB BANNISTER RL, 1988, ASME BARSOM JM, 1970, ASTM STP, V466, P281 BATES RC, 1981, CS1967 EPRI BATES RC, 1984, CS2932 EPRI BEGLEY JA, 1971, ASTM STP 2, V514 BEIGER C, 1993, 4 INT EPRI C IMPR CO BERGER C, 1994, 12 INT FORG C CHIC U BERGER C, 1994, COST 501 C MAT ADV P BHADESHIA HKD, 1993, MATH MODELLING WELD BOHNSTEDT, 1978, MASCHINENSCADEN, V51, P73 BOLTON JL, 1991, GS7250 EPRI, P6 BUSH SH, 1973, NUCL SAFETY, V14 CAMBELL CB, 1957, T ASME, V79, P1431 CHAMBERLIN HG, 1983, EDDYSTONE EXPERIENCE CHERUVU NS, 1989, METALL TRANS A, V20, P2345 CHERUVU SC, 1993, PWR21 ASME IJGC CLARK R, 1984, WELD REPAIR LOW PRES CLARK RE, 1985, AM POW C CHIC US APR CLARK RE, 1987, EPRI WORKSH WELD REP CLARK WG, 81JPGCPWR31 ASME CLARK WG, 1975, ASTM TESTING EVALUAT, V3 CONRAD JD, ASME CONROY RD, 1994, EPRI C WELD REP TECH COOL T, 1994, THESIS U CAMBRIDGE COULON A, 1990, P EPRI WORKSH TIT ST, P364 CURRAN RM, 1969, STRESS CORROSION CRA DEFOREST DR, ASME DEWEY RP, 1985, CS3891 EPRI DRAHY J, 1990, P EPRI WORKSH TIT ST, P405 EISENDER A, 1978, METALS TECHNOL FEB EMMERT HD, 1956, T ASME, V78, P1547 EWALD J, 1987, ADV MAT TECHNOLOGY F, P33 FISCHER GA, 1962, P ASTM, V62, P1137 FUJITA T, 1986, MET PROG AUG, P33 GELHAUS EF, 1978, EPRI J APR, P52 GRAY JL, P I MECH ENG, P329 GREENBERG D, 1970, ENG FRACT MECH, V1, P657 HARLOW JH, 1957, T ASME, V79, P1410 HESSAM K, 1971, CHEM PROCESS ENG, V52, P45 HIKADA K, 1994, P COST 501 MAT ADV P HILL R, 1994, UT THERM PLANT LIF M HOASHI J, 1990, P EPRI WORKSH TIT ST, P339 HODGE JM, 1979, P I MECH ENG, V193, P93 IKUJIRO K, 1991, 11 INT FORG M TERN I ISHIKI Y, 1990, P EPRI WORKSH TIT ST, P62 JONAS O, 1978, WEST STEAM TURB GEN KALDERON D, P I MECH ENG, P314 KANEKO R, 1990, P EPRI WORKSH TIT ST, P111 LARSON FR, 1952, T ASME, V74, P765 MAGDOWSKI RM, 1988, METALL T A, V19, P1583 MARLOW BA, 1995, 3 INT C PARS TURB C, P33 MCINTYRE P, 1995, P 3 INT C PARS TURB, P613 MEGANNON HE, 1983, ADV STEELMAKING PROC METALA MJ, 1988, ASME JPGC MORSON A, 1990, P EPRI WORKSH TIT ST, P92 MORSON A, 1991, GS7250 EPRI, P1 NAKABAYASHI Y, 1992, COST 501 C MAT POW E NAKASHAYASHI Y, 1990, COST C HIGH TEMP MAT ORTOLANO RJ, 1987, ADV MAT TECHNOLOGY F, P447 PARIS PC, 1964, P 10 SAGM ARM MAT RE POTTHAST E, 1994, 12 INT FORG M CHIC U RACE JM, 1992, MATER SCI TECH SER, V8, P875 RANKIN AW, 1956, T ASME, V78, P1527 RANKIN AW, 1956, T ASME, V78, P1603 REINHARD K, 1976, BROWN BOVERI REV, V63, P106 RUST TM, 1978, AM POW C CHIC APR 24 RUST TM, 1990, P EPRI WORKSH TIT ST, P149 SAXENA A, 1993, JSME INT J A-MECH M, V36, P1 SCHABTACH C, 1956, T ASME, V78, P1567 SCHAEFER AO, 1956, T ASME, V78, P1623 SCHMERLING JM, 1976, P AM POWER C, V38 SEARLIN RB, 1994, COST 501 C MAT ADV P SETH BB, 84MAT15 ASME SETH BB, 1995, P 3 INT C PARS TURB, P67 SOHRE JS, 1975, P 4 TURB S GAS TURB, P9 STELTZ WG, 1978, AF903 EPRI SUZUKI K, 1979, P 6 INT VAC MET C SP SWAMINATHAN VP, 1985, LIFE ASSESSMENT IMPR, P657 SWAMINATHAN VP, 1986, CS4516 EPRI TRUMPLER WE, 1960, T ASME, V82, P286 UGGOWITZER PJ, 1987, ADV MAT TECHNOLOGY F, P181 VISWANATHAN R, 1995, 3 INT C PARS TURB C, P229 WILLAMAN DO, 1987, P FOSS PLANT INSP C, P19 WINNE DH, 1958, T ASME, V80, P1643 YASUGAHIRA N, 1990, P EPRI WORKSH TIT ST, P385 NR 99 TC 0 PU INDIAN INST METALS PI CALCUTTA PA METAL HOUSE, PLOT 13/4, BLOCK AQ, SECTOR V, SALT LAKE, CALCUTTA 700 091, INDIA SN 0019-493X J9 TRANS INDIAN INST MET JI Trans. Indian Inst. Met. PD DEC PY 1997 VL 50 IS 6 BP 691 EP 718 PG 28 SC Metallurgy & Metallurgical Engineering GA ZJ933 UT ISI:000073268300026 ER PT J AU Jansson, SA Ostman, SO TI Status of PFBC and experience with materials performance during over 75 000 hours of operation in ABB'S PFBC plants SO MATERIALS AT HIGH TEMPERATURES LA English DT Article DE PFBC; materials; boiler tubing; gas turbine; coatings AB The key components of ABB's pressurized fluidized bed combined cycle (PFBC) plants are the specially designed gas turbine, which we refer to as the PFBC machine, and the pressurized fluidized bed boiler used to generate and superheat steam for expansion in a steam turbine. ABB Stal's 17 MWe GT35P and 70 MWe GT140P PFBC machines, respectively, are used in ABB's 100 MWe P200 and 425 MWe P800 modules. Particulate cleanup before expansion in the turbine sections is with cyclones. So far, over 75 000 hours of operation has been accumulated on P200 modules in the world's first PFBC plants, demonstrating that PFBC meets expectations. The GT35P machines have been found to perform as expected, although high cycle fatigue failures of the variable speed low pressure turbine blades have been experienced in the Tidd and Vartan plants, leading to minor modifications of the blades and also to a change of blade material. Following the observation of some wear of turbine blading in the GT35P machines, and as originally planned while these machines were being designed, erosion protective coatings have been applied at locations where secondary flows and the formation of vortices causes enhanced interaction between particulates and the turbine components. Wear on boiler tubing and membrane walls has been very limited, certainly no more severe than is typical for AFBC units, and found to be controllable through use of coatings, in the case of evaporator and other low temperature component surfaces, or by the application of sleeves at locations with enhanced tube-particle interaction. The flame sprayed Metcoloy-2 coating originally applied to all evaporator tubing has performed very well in the Tidd plant, whereas some very local flaking of this coating has been noted in the Escatron plant. By comparison, extensive flaking of this coating has occurred in the Vartan plant. This was found to involve oxidation of the bonding layer under the micro porous flame-sprayed coating, and embrittlement of the Metcoloy-2 layer. It is believed that differences in operating conditions, i.e., in surface temperature and corrosive environment, may explain these differences in performance. During the summer of 1996, the tube bundle in one of the two boilers at Vartan was replaced with a new tube bundle, in which the evaporator tubing has a sprayed and fused coating, which should be impervious to the combustion,eases. Together, the experiences obtained in the different plants provide a very significant database which is applied for the continued improvement of existing plants and also in the design of new plants. The next P200 plant will be built in Germany for operation on brown coal. The first P800 plant will be built at the Karita site of Kyushu Electric Power Company, Japan. The GT140P machine for that plant has already been manufactured and is now being shop tested at the ABB Stal workshops in Finspong, before shipment to Japan. The new P800 boiler is being manufactured at IHI's Aioi factories in Japan. Future development of ABB's PFBC plants is foreseen to include raising the turbine inlet temperature through combustion of a topping fuel in order to reach thermal efficiencies which ultimately may be in the range of 50-53% (LHV). Otherwise, the main attention is focussed on improved availability, and further enhanced performance and fuel flexibility. RP Jansson, SA, ABB CARBON AB,S-61282 FINSPANG,SWEDEN. CR BAUER DA, 1995, P POW GEN AM 95 C BO, V2, P109 EGNELL R, 1992, OPERATING EXPERIENCE, V7, P149 GOTO H, 1995, P 13 INT C FLUID BED, V2, P911 JANSSON SA, 1995, P EPRI C NEW POW GEN JANSSON SA, 1996, ASME TURB AS C 5 7 N KYRKLUND B, 1977, THESIS TU HELSINKI F MARROCCO M, 1995, P US DEP EN 4 ANN CL MARTINI M, 1995, EARLY DEV PARENTING, V4, P113 MUDD MJ, 1995, P 13 INT C FLUID BED, V2, P925 NR 9 TC 0 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 2 BP 95 EP 99 PG 5 SC Materials Science, Multidisciplinary GA YF664 UT ISI:A1997YF66400006 ER PT J AU Swaminathan, VP Allen, JM Touchton, GL TI Temperature estimation and life prediction of turbine blades using post-service oxidation measurements SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB The depth of internal oxidation and nitridation from the surface of the 16 cooling holes in a first-stage turbine blade was measured by optical microscopy after 32,000 hours of service. Maximum depth of penetration was 15.5 mils (0.4 mm) at the trailing edge hole. An effort was made to predict hole surface metal temperatures based on these measurements using the Arrhenius relationship between time and temperature with depth of oxidation assumed to be parabolic with time. Reasonable correlations were obtained between finite element analysis results and temperature estimates based on the oxidation measurements. In the thickest part of the airfoil, where metal temperature is minimum, intergranular cracks rtp to 12.6 mils (0.32 mm) in depth were found at the surface of the cooling holes, Measurable oxidation attack was only one to two mils (0.025-0.050 mm). Based on an approximate elastic-relaxation-local inelastic stress analysis, it was calculated that inelastic local strains of over one percent occur at the points of cracking. No cracking was observed in the more heavily oxidized, lower stressed, hotter holes, However, cracking occurred in a trailing edge tip cooling hole when weld repair of the rip squealer was attempted, doe to embrittlement and grain boundary oxidation from service exposure. Temperature estimates suitable for rife assessment purposes using oxidation measurements appears to be a possible technique that should be further developed and validated. C1 ELECT POWER RES INST,PALO ALTO,CA 94304. RP Swaminathan, VP, SW RES INST,6220 CULEBRA RD,SAN ANTONIO,TX 78228. CR *NICK DEV I, 1987, NICK BAS ALL *SPEC MET CORP, UD 520 ALL PERF DAT ALLEN JM, 1982, ASME, V104, P349 CHANG WH, 1972, SUPERALLOYS FOX HM, 1990, P EPRI ASM LIF ASS R, P344 GRIFFE W, 1963, PRODUCT ENG 1111, P112 LEE SY, 1972, ASME, V94, P149 NEUBER H, 1961, J APPLIED MECHANICS, V28, P544 PETERSON RE, 1953, STRESS CONCENTRATION, P94 TIMOSHENKO S, 1951, THEORY ELASTICITY, P399 TIMOSHENKO S, 1956, STRENGTH MAT 2, P530 WAN SM, 1994, 94GT270 ASME WHIDDEN GL, 1992, 92GT397 ASME WHITLOW GA, 1984, J ENG MATER-T ASME, V106, P43 WOODFORD DA, 1990, P EPRI ASM LIF ASS R, P97 NR 15 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1997 VL 119 IS 4 BP 922 EP 929 PG 8 SC Engineering, Mechanical GA YD474 UT ISI:A1997YD47400022 ER PT J AU [Anon] TI Dual surface coatings extend life of steam turbine blades SO PROFESSIONAL ENGINEERING LA English DT News Item NR 0 TC 0 PU MECHANICAL ENG PUBL LTD PI EDMUNDS PA PO BOX 24, NORTHGATE AVE, BURY ST, EDMUNDS, SUFFOLK, ENGLAND IP32 6BW SN 0953-6639 J9 PROF ENG JI Prof. Eng. PD OCT 1 PY 1997 VL 10 IS 18 BP 38 EP 38 PG 1 SC Engineering, Mechanical GA YA350 UT ISI:A1997YA35000043 ER PT J AU Kameda, J Bloomer, TE Sugita, Y Ito, A Sakurai, S TI Mechanical properties of aluminized CoCrAlY coatings in advanced gas turbine blades SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE aluminized CoCrAlY coatings; layered microstructure; small punch testing method and ductility ID SMALL-PUNCH AB The microstructure/composition and mechanical properties (22-950 degrees C) in aluminized CoCrAIY coatings of advanced gas turbine blades have been examined using scanning Auger microprobe and a small punch (SP) testing method. Aluminized coatings were made of layered structure divided into four regions; (I) Al enriched and Cr depleted region, (II) Al and Cr graded region, (III) fine grained microstructure with a mixture of Al and Cr enriched phases and (IV) Ni/Co interdifusion zone adjacent to the interface. Coating regions I and II with high microhardness showed easier formation of brittle cracks in a wide temperature range, compared to regions III and IV. The coating region III had lower room temperature ductility and conversely higher elevated temperature ductility than the region IV due to a precipitous ductility increase above 730 degrees C. The integrity of aluminized coatings while in-service is discussed in light of the variation in the low cycle fatigue life as well as the ductility in the layered structure. (C) 1997 Elsevier Science S.A. C1 IOWA STATE UNIV SCI & TECHNOL,CATD,AMES,IA 50011. CHUBU ELECT POWER CO INC,ELECT POWER R&D CTR,NAGOYA,AICHI 458,JAPAN. HITACHI LTD,MECH ENGN RES LAB,HITACHI,IBARAKI 317,JAPAN. RP Kameda, J, IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. CR BAIK JM, 1983, SCRIPTA METALL, V17, P1143 BERNSTEIN LH, 1993, ASTM SPECIAL TECHNIC, V1186, P212 CHERUVU NS, 1996, JOM-J MIN MET MAT S, V48, P34 KAMEDA J, IN PRESS MAT SCI E A KAMEDA J, 1992, J MATER SCI, V27, P983 KAMEDA J, 1997, ASME TURBO EXPO 97 MAO XY, 1987, J NUCL MATER, V150, P42 PATNAIK PC, 1994, ADV HIGH TEMPERATURE, P169 SEAH MP, 1983, PRACTICAL SURFACE AN, P181 SUGITA Y, 1996, MAT AGEING COMPONENT, P307 SUGITA Y, 1996, MATER MANUF PROCESS, V10, P987 NR 11 TC 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 30 PY 1997 VL 234 BP 489 EP 492 PG 4 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA XV252 UT ISI:A1997XV25200118 ER PT J AU Laino, DJ Hansen, AC TI An integrated approach to wind turbine fatigue analysis SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID PLANETARY BOUNDARY-LAYER; VELOCITY SPECTRA; SURFACE-LAYER AB The wind turbine dynamics codes YawDyn and ADAMS have been interfaced with the LIFE2 code for fatigue life estimation via a new interface program, Dyn2LIFE. This work is sponsored by the National Renewable Energy Laboratory (NREL) with the intent of making it straightforward and practical for wind turbine designers to determine those aspects of their design and wind environment that will cause the most fatigue damage. Several parameters suspected of affecting turbine fatigue life are investigated through a model of the NREL Phase III Combined Experiment Rotor. This study proved the Dyn2LIFE code useful in creating LIFE2 input from YawDyn and ADAMS output, and also revealed some areas of possible expansion and improvement. Results from this study of a steel blade root suggest changes affecting the normal operation of the turbine alter fatigue life more than rare, high load events. Understanding how the material fatigue characteristics affect lifetime estimates is discussed in terms of the S-N curve utilized in this study. This paper presents the first results from an ongoing project. In the future, we plan to analyze a variety of turbine configurations to help identify those variables which may have the greatest influence on fatigue life. RP Laino, DJ, UNIV UTAH,DEPT MECH ENGN,SALT LAKE CITY,UT 84112. CR *INT EL COMM, 1994, 14001 IEC BUHL ML, 1995, WIND ENERGY 1995 HANSEN AC, 1992, NRELTP04424822 U UT HOJSTRUP J, 1982, J ATMOS SCI, V39, P2239 KAIMAL JC, 1972, Q J R METEOROL SOC, V98, P563 KAIMAL JC, 1978, J ATMOS SCI, V35, P18 KELLEY ND, 1993, WIND ENERGY 1993 MALCOLM DJ, 1994, WIND ENERGY 1994 OLESEN HR, 1984, BOUND-LAY METEOROL, V29, P285 SCHLUTER LL, 1989, SAND891396 SAND NAT SCHLUTER LL, 1991, SAND902259 SAND NAT SCHLUTER LL, 1991, SAND902260 SAND NAT SIMMS DA, 1995, WIND ENERGY 1995 SUTHERLAND HJ, 1989, P WINDPOWER 89 SUTHERLAND HJ, 1989, SAND891397 SAND NAT VEERS PS, 1989, 8 ASME WIND EN S HOU WINTERSTEIN SR, 1995, SAND943039 SAND NAT WRIGHT AD, 1996, WIND ENERGY NR 18 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 1997 VL 119 IS 3 BP 242 EP 247 PG 6 SC Energy & Fuels; Engineering, Mechanical GA XT781 UT ISI:A1997XT78100009 ER PT J AU Taslim, ME Li, T Spring, SD TI Measurements of heat transfer coefficients and friction factors in rib-roughened channels simulating leading-edge cavities of a modern turbine blade SO JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME LA English DT Article AB Lending edge cooling cavities in modern gas turbine blades play an important role in maintaining the leading edge temperature at levels consistent with airfoil design life. These cavities often have a complex cross-sectional shape to be compatible with the external contour of the blade at the leading edge. A survey of many existing geometries shows that, for analytical as well as experimental analyses, such cavities can be simplified in shape by a four-sided polygon with one curved side similar to the leading edge curvature, a rectangle with one semicircular side (often the smaller side) or a trapezoid, the smaller base of which is replaced by a semicircle. Furthermore, to enhance the heat transfer coefficient in these cavities, they are mostly roughened on three sides with ribs of different geometries. Experimental data on friction factors and heat transfer coefficients in such cavities are rare if not nonexistent. A liquid crystal technique was used in this experimental investigation To measure heat transfer coefficients in six test sections representing the leading-edge cooling cavities. Both straight and tapered ribs were configured on the two opposite sidewalls in a staggered arrangement with angles of attack to the mainstream flow, alpha, of 60 and 90 deg. The ribs on the curved surface were of constant cross section with an angle of attack 90 deg to the flow. Heat transfer measurements were performed on the straight sidewalls, as well as on the round surface adjacent to the blade leading edge. Effects such as rib angle of attack to the mainstream and constant versus tapered rib cross-sectional areas were also investigated. Nusselt numbers, friction factors, and thermal performances are reported for nine rib geometries in six rest sections. C1 GE AIRCRAFT ENGN,LYNN,MA 02190. RP Taslim, ME, NE UNIV,DEPT MECH ENGN,BOSTON,MA 02115. CR BURGGRAF F, 1970, AUGMENTATION CONVECT, P70 CHANDRA PR, 1988, ASME, V110, P233 CHANDRA PR, 1989, AIAA J THERMOPHYSICS, V3, P315 DITTUS FW, 1930, U CALIF BERKELEY PUB, V2, P443 DUTTA S, 1994, ASME WINT ANN M ELHUSAYNI HA, 1994, ASME, V113, P75 HAN JC, 1978, INT J HEAT MASS TRAN, V21, P1143 HAN JC, 1984, ASME, V106, P774 HAN JC, 1985, J ENG GAS TURB POWER, V107, P628 HAN JC, 1992, ASME, V114, P872 KLINE SJ, 1953, MECH ENG, V75, P3 METZGER DE, 1983, P ASME JSME THERMAL, V1, P429 METZGER DE, 1987, 1987 P ASME JSME THE, V3, P327 METZGER DE, 1987, EXPT HEAT TRANSFER, V1, P31 METZGER DE, 1988, TRANSPORT PHENOMENA METZGER DE, 1990, COMPACT HEAT EXCHANG, P151 MOFFAT RJ, 1990, 9TH P INT HEAT TRANS, V1, P187 MOODY LF, 1944, T AM SOC MECH ENG, V66, P671 TASLIM M, 1991, EASME, V113, P346 TASLIM ME, 1988, AIIAA883014 TASLIM ME, 1988, P ASME NAT HEAT C HO TASLIM ME, 1990, P IEEE ELECTROR 90 B TASLIM ME, 1991, AIAA912033 TASLIM ME, 1991, ASME, V113, P75 TASLIM ME, 1997, ASME, V119, P381 WEBB RL, 1971, INT J HEAT MASS TRAN, V14, P601 ZHANG YM, 1994, J HEAT TRANS-T ASME, V116, P58 NR 27 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0889-504X J9 J TURBOMACH-T ASME JI J. Turbomach.-Trans. ASME PD JUL PY 1997 VL 119 IS 3 BP 601 EP 609 PG 9 SC Engineering, Mechanical GA XQ503 UT ISI:A1997XQ50300027 ER PT J AU Anagnostopoulos, J Bergeles, G TI Numerical investigation of the grinding process in a beater wheel mill with classifier SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID LADEN GAS-FLOWS; ROUND JET; PARTICLE; EROSION; TURBULENT; TURBINES; MODEL AB A numerical investigation is presented for a two-dimensional simulation of the gas flow field and of the dynamic behavior of lignite particles inside Beater Wheel mills with classifier, installed in large coal-fired plants. A large number of representative particles are tracked using Lagrangian equations of motion, in combination with a stochastic model for particle turbulent dispersion. All the important mechanisms associated with the particle motion through the mill (particle-surface collisions and rebounding phenomena, fuel moisture evaporation and erosion wear of internal surfaces) are modeled. A special model is constructed to simulate the fragmentation of impacting particles and to calculate the size distribution of the final mill product. The models are regulated on the basis of available data from grinding mills of the Greek lignite power stations. The numerical code is capable of predicting the locations of significant erosion and to estimate the amount of particle mass that circulates through the mill via the classifying chamber. Mean impact velocity and impingement angle distributions along all the internal surfaces are also provided. The results indicate remarkable differences in the extent of the erosion caused at different locations of the mill. Also, the significant role of the leading blades arrangement inside the classifier on its classification performance and efficiency is elucidated. RP Anagnostopoulos, J, NATL TECH UNIV ATHENS,DEPT MECH ENGN,LAB AERODYNAM,ZOGRAFOS 15700,ATHENS,GREECE. CR ANAGNOSTOPOULOS J, 1992, INT J HEAT FLUID FL, V13, P287 AUSTIN LG, 1984, PROCESS ENG SIZE RED BEACHER B, 1982, ASME J ENG POWER, V104, P64 DIAKOUMAKOS H, 1988, NATO ASI SERIES E, P449 FAN JR, 1991, CHEM ENG COMMUN, V104, P209 FOUNTI M, 1993, P 2 INT C COMB TECHN, V2, P34 GOODWIN JE, 1969, P I MECH ENGRS LONDO, V184, P279 GRANT G, 1975, J AIRCRAFT, V12, P471 HAMED A, 1992, J ENG GAS TURB POWER, V114, P235 HUMPHREY JAC, 1990, INT J HEAT FLUID FL, V11, P170 LAITONE JA, 1979, WEAR, V56, P239 LAITONE JA, 1983, J AIRCRAFT, V20, P275 LAUNDER BE, 1972, MATH MODELS TURBULEN LAUNDER BE, 1974, COMPUTER METHODS APP, V3, P269 MCINTOSH MJ, 1976, BRAUNKOHLE, V12, P433 MENGUTURK M, 1983, J FLUID ENG-T ASME, V105, P270 PATANKAR SV, 1972, INT J HEAT MASS TRAN, V15, P1787 PATANKAR SV, 1980, NUMERICAL HEAT TRANS PAUW OG, 1988, POWDER TECHNOL, V56, P251 POPPLEWELL LM, 1992, POWDER TECHNOL, V70, P21 RAASK E, 1988, EROSION WEAR COAL UT SARGIANOS NP, 1993, INT J NUMER METH FL, V16, P287 SCHUH MJ, 1989, AICHE J, V35, P466 SHUEN JS, 1983, AICHE J, V29, P167 TABAKOFF W, 1991, J ENG GAS TURB POWER, V113, P607 TASSERIE M, 1992, POWDER TECHNOL, V73, P61 TILLY GP, 1969, WEAR, V14, P63 TILLY GP, 1970, WEAR, V16, P447 UEMOIS H, 1975, WEAR, V31, P359 NR 29 TC 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1997 VL 119 IS 3 BP 723 EP 733 PG 11 SC Engineering, Mechanical GA XQ142 UT ISI:A1997XQ14200032 ER PT J AU Rigney, DV Viguie, R Wortman, DJ Skelly, DW TI PVD thermal barrier coating applications and process development for aircraft engines SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE electron beam physical vapor deposition; high-pressure turbine airfoils; process parameters; thermal barrier coatings; yttria-stabilized zirconia ID THICK AB Thermal barrier coatings (TBCs) have been developed for application to aircraft engine components to improve service life in an increasingly hostile thermal environment. The choice of TBC type is related to the component, intended use, and economics. Selection of electron beam physical vapor deposition processing for turbine blade is due in part to part size, surface finish requirements, thickness control needs, and hole closure issues, Process development of PVD TBCs has been carried out at several different sites, including GE Aircraft Engines (GEAE). The influence of processing variables on microstructure is discussed, along with the GEAE development coater and initial experiences of pilot line operation. C1 GE AIRCRAFT ENGINES,CINCINNATI,OH 45215. CR MEIER SM, 1992, 92GT203 ASME MOVCHAN BA, 1969, PHYS MET METALLOGR, V28, P83 THORNTON JA, 1974, J VAC SCI TECHNOL, V11, P666 THORNTON JA, 1977, ANNU REV MATER SCI, V7, P239 WORTMAN DJ, 1989, MAT SCI ENG A-STRUCT, V121, P433 NR 5 TC 31 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHNOL JI J. Therm. Spray Technol. PD JUN PY 1997 VL 6 IS 2 BP 167 EP 175 PG 9 SC Materials Science, Coatings & Films GA XD633 UT ISI:A1997XD63300013 ER PT J AU Maricocchi, A Bartz, A Wortman, D TI PVD TBC experience on GE aircraft engines SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE microstructure; performance; PVD coatings; TBCs AB The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine, The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings have been used for many years to increase the reliability of gas turbine engine components, Recent experience with the physical vapor deposition process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles, Engine test results of turbine components with a 125 mu m (0.005 in.) PVD TBC have demonstrated component operating temperatures of 56 to 83 degrees C (100 to 150 degrees F) lower than non-PVD TBC components. Engine testing has also revealed that TBCs are susceptible to high angle particle impact damage, Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes in local areas, Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area; however, a significant temperature reduction was realized over an airfoil without TBC. C1 GE AIRCRAFT ENGINES,CINCINNATI,OH 45215. CR BUSH R, 1974, P 1974 GAS TURB MAR DEMASIMARCIN JT, 1990, J ENG GAS TURB POWER, V112, P521 JOHNER G, 1985, J VAC SCI TECHNOL, P2516 JOHNSON C, UNPUB MEIER SM, ASME C PUBLICATION WORTHMAN DJ, 1989, MAT SCI ENG A-STRUCT, V121, P443 NR 6 TC 20 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHNOL JI J. Therm. Spray Technol. PD JUN PY 1997 VL 6 IS 2 BP 193 EP 198 PG 6 SC Materials Science, Coatings & Films GA XD633 UT ISI:A1997XD63300017 ER PT J AU Vyas, NS Sidharth Rao, JS TI Dynamic stress analysis and a fracture mechanics approach to life prediction of turbine blades SO MECHANISM AND MACHINE THEORY LA English DT Article AB Emerging blade technologies are finding it increasingly essential to correlate blade vibrations to blade fatigue in order to assess the residual life of existing blading and for development of newer designs. In this paper an analytical code for dynamic stress analysis and fatigue life prediction of blades is presented. The life prediction algorithm is based on a combination method, which combines the local strain approach to predict the initiation life and fracture mechanics approach to predict the propagation life, to estimate the total fatigue life. The conventional stress based approach involving von Mises theory along with S-N-Mean stress diagram suffers from the drawback that it does not make allowance for the possibility of development of plastic strain zones, especially in cases of low cycle fatigue. In the present paper, strain life concepts are employed to analyse the crack initiation phenomenon. Dynamic and static stresses incurred by the blade form inputs to the life estimation algorithm. The modeling is done for a general tapered, twisted and asymmetric cross section blade mounted on a rotating disc at a stagger angle. Blade damping is non-linear in nature and a numerical technique is employed for estimation of blade stresses under typical nozzle excitation. Critical cases of resonant conditions of blade operation are considered. Neuber's rule is applied to the dynamic stresses to obtain the elasto-plastic strains and then the material hysteresis curve is used to iteratively solve for the plastic stress. Static stress effects are accounted for and crack initiation life is estimated by solving the strain life equation. Crack growth formulations are then applied to the initiated crack to analyse the propagation of crack leading to failure. The engineering approximations involved are stated and the algorithm is numerically demonstrated for typical conditions of blade operations. (C) 1997 Elsevier Science Ltd. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. RP Vyas, NS, INDIAN INST TECHNOL,DEPT MECH ENGN,KANPUR 208016,UTTAR PRADESH,INDIA. CR BASQUIN OH, 1910, P AM SOC TEST MATER, V10, P625 COFFIN LF, 1954, T ASME, V76, P931 DOWLING NE, 1979, ASTM STP, V677, P247 IRRETIER H, 1986, P IFTOMM INT C ROT D, P301 IRRETIER H, 1991, SESS P FORC VIBR TUR JONES DIG, 1983, ASME VIR C, P137 MACBAIN JC, 1984, J VIB ACOUST, V106, P218 MANSON SS, 1953, HEAT TRANSF S U MICH, P9 MASSING G, 1926, P 2 IN C APL MECH ZU MORROW J, 1968, FATIGUE DESIGN HDB A, V4, P21 MURAKAMI Y, 1987, STRESS INTENSITY FAC, V1 MURAKAMI Y, 1987, STRESS INTENSITY FAC, V2 NEUBER H, 1964, T ASME E, V28, P544 OSGOOD CC, 1982, FATIGUE DESIGN PARIS PC, 1963, T ASME D, V85, P528 PETERSON RE, 1974, STRESS CONCENTRATION RAO JS, 1986, P IFTOMM INT C ROT D, P269 RAO JS, 1986, P IFTOMM TECH COMM R RAO JS, 1986, P SHOCK VIBR B US NA, V56, P109 RAO JS, 1987, SHOCK VIBRATION DIGE, V19, P3 RAO JS, 1989, 89GT27 ASME RAO JS, 1990, 90GT269 ASME RIEGER NF, 1980, EPRI C NDE STEAM TUR RIEGER NF, 1985, SHOCK VIBRATION B 1, V55, P51 ROARK RJ, 1976, FORMULAS STRESS STRA SINHA A, 1984, J ENG GAS TURB POWER, V106, P65 SOCIE DF, 1984, ASTM, P284 SRINIVASAN AV, 1984, J VIB ACOUST, V106, P165 VYAS NS, P 7 IFTOMM WORLD C S, P697 VYAS NS, 1992, 92GT78 ASME NR 30 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-114X J9 MECH MACH THEOR JI Mech. Mach. Theory PD MAY PY 1997 VL 32 IS 4 BP 511 EP 527 PG 17 SC Engineering, Mechanical GA WT051 UT ISI:A1997WT05100008 ER PT J AU Faller, WE Schreck, SJ TI Unsteady fluid mechanics applications of neural networks SO JOURNAL OF AIRCRAFT LA English DT Article ID PREDICTION AB The capability to harness or alleviate unsteady aerodynamic forces and moments could dramatically enhance aircraft control during severe maneuvers as well as significantly extend the life span of both helicopter and wind turbine blade/rotor assemblies, Using recursive neural networks, time-dependent models that predict unsteady boundary-layer development, separation, dynamic stall, and dynamic reattachment have been developed, Further, these models of the flow-wing interactions can be used as the foundation upon which to develop adaptive control systems. The present work describes these capabilities for three-dimensional unsteady surface pressures and two-dimensional unsteady shear-stress measurements obtained for harmonic and constant-rate pitch motions. In the near future, it is predicted that such techniques will provide a viable approach for the development of six degree-of-freedom motion simulators for severe vehicle maneuvers as well as a foundation for the active control of unsteady fluid mechanics in a variety of systems. C1 JOHNS HOPKINS UNIV,DEPT MECH ENGN,BALTIMORE,MD 21218. USAF,OFF SCI RES,DEPT MATH,WASHINGTON,DC 20332. CR AHMED S, 1991, 913225 AIAA CARR L, 1985, 3 S NUM PHYS ASP AER CARR LW, 1988, J AIRCRAFT, V25, P6 CARR LW, 1992, INT UN THEOR APPL ME ERICSSON LE, 1988, 880564 AIAA FALLER WE, 1995, J AIRCRAFT, V32, P1177 FALLER WE, 1995, J AIRCRAFT, V32, P1213 FALLER WE, 1996, 962492 AIAA FALLER WE, 1996, PROG AEROSP SCI, V32, P433 JACOBS JH, 1994, J AIRCRAFT, V31, P831 KNIGHT D, 1993, 932977 AIAA LINSE D, 1992, 920172 AIAA LORBER P, 1991, 911795 AIAA LORBER P, 1992, 5 S NUM PHYS ASP AER NIVEN AJ, 1989, VERTICA, V13, P187 NIVEN AJ, 1990, 90343 INT COUNC AER ROBINSON M, 1988, P WORKSH 2 UNST SEP, P225 ROBINSON M, 1995, 950526 AIAA SCHRECK S, 1991, 911793 AIAA SCHRECK SJ, 1994, 942256 AIAA SCHRECK SJ, 1994, 943426 AIAA SCHRECK SJ, 1994, J AIRCRAFT, V31, P899 SCHRECK SJ, 1995, J AIRCRAFT, V32, P178 SEWALL WG, 1988, NEW MULTIPOINT THIN STECK J, 1992, 920048 AIAA WILDER M, 1993, 932978 AIAA NR 26 TC 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 1997 VL 34 IS 1 BP 48 EP 55 PG 8 SC Engineering, Aerospace GA WP100 UT ISI:A1997WP10000008 ER PT J AU Miller, RA TI Thermal barrier coatings for aircraft engines: History and directions SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE historical review; thermal barrier coatings; zirconia ID TURBINE-BLADES; ALLOYS; MODEL; LIFE AB Thin thermal barrier coatings (TBCs) for protecting aircraft turbine section airfoils are examined. The discussion focuses on those advances that led first to TBC use for component life extension and more recently as an integral part of airfoil design, Development has been driven by laboratory rig and furnace testing, corroborated by engine testing and engine field experience, The technology has also been supported by performance modeling to demonstrate benefits and life modeling for mission analysis. Factors that have led to the selection of current state-of-the-art plasma-sprayed and physical-vapor-deposited zirconia-yttria/MCrAlX TBCs are emphasized, as are observations fundamentally related to their behavior, Current directions in research into TBCs and recent progress at NASA are also noted. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. CR ANDERSON NP, 1983, NASACR168251 ANDRESS DE, 1978, NASACR135359 AULT NN, 1957, J AM CERAM SOC, V40, P69 BERNDT CC, 1992, J THERM SPRAY TECHN, V1, P341 BOCH P, 1984, ADV CERAM, V12, P488 BRATTON RJ, 1982, CR165545 NASA BRINDLEY WJ, 1990, SURF COAT TECH, V43, P446 BRINDLEY WJ, 1993, MAT SCI ENG A-STRUCT, V163, P33 CANNISTRARO NJ, 1958, MET PROG, V174, P111 CHANG GC, 1987, SURF COAT TECH, V30, P13 CHUANXIAN D, 1984, THIN SOLID FILMS, V118, P467 CRUSE TA, 1988, J ENG GAS TURB POWER, V110, P610 CURREN AN, 1972, NASATMX2461 DAVIES H, 1963, J R AERONAUT SOC, V67, P79 DEMARAY RE, 1981, P 2 C ADV MAT ALT FU DEMASI JT, 1989, CR182230 NASA DEMASIMARCIN JT, 1989, ASME89GT132 NASA DENNIS PR, 1965, NASASP5033, P117 DUDERSTADT EC, 1983, CR168037 NASA DUVALL DS, 1981, P 2 C ADV MAT ALT FU, P6 GARRETT FG, 1953, NACARME52130 GLADDEN HJ, 1980, NASATP1598 GOWARD GW, 1987, P 1987 COAT ADV HEAT, P1 GRISAFFE SG, 1967, MACH DES, V39, P174 HARRISON WN, 1947, NACATN1186 HILLERY RV, 1988, CR180807 NASA HJELM LN, 1961, NASATMX7072, P227 HUMINK J, 1963, HIGH TEMPERATURE INO, P14 INGHAM HS, 1964, METCO FLAME SPRAY HD, V3 LAMMERMANN H, 1991, ADV MATER PROCESS, V140, P18 LEE KN, 1994, ADV CERAMIC MATRIX C, P565 LEE KN, 1994, MRS BULL, V19, P35 LEVINE SR, 1982, TM85349 NASA LEVY AV, 1959, MET PROG, V75, P86 LIEBERT CH, 1976, NASATMX3352 LIEBERT CH, 1976, TMX3410 NASA LOWELL CE, 1976, MET T A, V7, P655 MCPHERSON R, 1981, THIN SOLID FILMS, V83, P807 MEIER SM, 1990, P 1990 COAT ADV HEAT, P57 MEIER SM, 1991, CR18911 NASA MEITNER PL, 1978, TP1310 NASA MILLER RA, 1982, THIN SOLID FILMS, V95, P265 MILLER RA, 1983, AM CERAM SOC BULL, V62, P1355 MILLER RA, 1984, J AM CERAM SOC, V67, P517 MILLER RA, 1988, 12 NASA, P1 MILLER RA, 1989, J ENG GAS TURB POWER, V3, P301 MILLER RA, 1991, TM105923 NASA MILLER RA, 1992, J THERM SPRAY TECHN, V1, P211 MILLER RA, 1993, TP3296 NASA MILLER RA, 1994, THERMAL SPRAY IND AP, P49 SHANAR R, 1987, P 1987 COAT ADV HEAT, P43 SIEMERS PA, 1981, CR165351 NASA SIMS CT, 1991, ADV MATER PROCESS, V139, P32 STECURA S, 1976, TMX3425 NASA STECURA S, 1977, 4055705, US STECURA S, 1977, AM CERAM SOC B, V56, P1082 STECURA S, 1978, TM78976 NASA STECURA S, 1985, TM87062 NASA STECURA S, 1987, THIN SOLID FILMS, V150, P15 STRANGMAN TE, 1987, CR179648 NASA STRANGMAN TE, 1987, P 1987 COAT ADV HEAT, P63 STUBICAN VS, 1984, ADV CERAM, V12, P96 STUBICAN VS, 1988, ADV CERAM, V24, P71 SUMNER IE, 1980, 801193 AIAA TAYLOR TA, 1990, SURF COAT TECH, V43, P470 TORIZ FC, 1988, ASME88GT279 NASA TUCKER RC, 1976, 3 C GAS TURB MAT MAR WHEILDON WM, 1961, 3006782, US WILKES KE, 1973, CR121144 NASA WORTMAN DJ, 1989, ASME89GT134 NR 70 TC 79 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHNOL JI J. Therm. Spray Technol. PD MAR PY 1997 VL 6 IS 1 BP 35 EP 42 PG 8 SC Materials Science, Coatings & Films GA WM436 UT ISI:A1997WM43600004 ER PT J AU Bose, S DeMasiMarcin, J TI Thermal barrier coating experience in gas turbine engines at Pratt & Whitney SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE EB-PVD; gas turbine engine; plasma spray; TBC; thermal barrier AB Pratt & Whitney has accumulated more than three decades of experience with thermal barrier coatings (TBCs), These coatings were originally developed to reduce surface temperatures of combustors of JT8D gas turbine engines to increase the thermal fatigue life of the components, Continual improvements in design, processing, and properties of TBCs have extended their applications to other turbine components, such as vanes, vane platforms, and blades, with attendant increases in performance and component durability, Plasma-spray-based generation I (Gen I) combustor TBCs with 7 wt % yttria partially stabilized zirconia deposited by air plasma spray (APS) on an APS NiCoCrAlY bond coat continues to perform extremely well in all product line engines, Durability of this TBC has been further improved in Gen II TBCs for vanes by incorporating low-pressure chamber plasma-sprayed NiCoCrAlY as a bond coat, The modification has improved TBC durability by a factor of 2.5 and altered the failure mode from a ''black failure'' within the bond coat to a ''white failure'' within the ceramic. Further improvements have been accomplished by instituting a more strain-tolerant ceramic top layer with electron beam/physical vapor deposition (EB-PVD) processing, This Gen III TBC has demonstrated exceptional performance on rotating airfoils in high-thrust-rated engines, improving blade durability by three times through elimination of blade creep, fracture, and rumpling of metallic coatings used for oxidation protection of the airfoil surfaces, A TBC durability model for plasma-sprayed as well as EB-PVD systems is proposed that involves the accumulation of compressive stresses during cyclic thermal exposure, The model attempts to correlate failure of the various TBCs with elements of their structure and its degradation with thermocyclic exposure. C1 PRATT & WHITNEY CO,E HARTFORD,CT 06108. CR DEMASI JT, 1989, CR182230 NASA LEW RE MEIER SM, 1994, J ENG GAS TURB POWER, V116, P250 MILLER RA, 1982, THIN SOLID FILMS, V95, P265 NR 3 TC 39 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHNOL JI J. Therm. Spray Technol. PD MAR PY 1997 VL 6 IS 1 BP 99 EP 104 PG 6 SC Materials Science, Coatings & Films GA WM436 UT ISI:A1997WM43600012 ER PT S AU Heimann, RB TI Applications of plasma-sprayed ceramic coatings SO ADVANCED CERAMIC MATERIALS SE KEY ENGINEERING MATERIALS LA English DT Review DE ceramic coatings; plasma spraying; wear-; corrosion-; thermal barrier-; bioceramic- and electronic functional coatings ID THERMAL BARRIER COATINGS; HIGH-TEMPERATURE EROSION; TURBINE BLADES; CREEP-BEHAVIOR; TECHNOLOGY; CORROSION; ALLOY; MECHANISMS; INTERFACE; APATITE AB Plasma spraying encompasses a variety of surface engineering processes by which solid materials (wire, rods, powder particles) are heated by a plasma jet, melted and propelled against the substrate to be coated. Rapid solidification of the molten particles composed of metals, ceramics, polymers and composite materials at the substrate surface builds up, splat by splat, a layer whose various functions include protection against wear, erosion, corrosion and thermal or chemical degradation but also impart special electronical, magnetic or decorative properties to the substrate/coating system. Also, thick coatings are being applied in many industrial sectors to restore or attain desired workpiece dimensions and specifications. RP Heimann, RB, FREIBURG UNIV MIN & TECHNOL,INST MINERAL,BRENNHAUSGASSE 14,D-09599 FREIBERG,GERMANY. CR 1983, CS3139 EPRI, V1 1991, ADV MAT PROCESSES, V139, P6 *BUND FORSCH TECHN, 1994, NEUE MAT SCHL 21 JAH *CTR EC COMP, 1990, ASS ALB TECHN CTR *GORH ADV MAT I, 1988, ADV MAT PROCESSES, V1, P30 *GORH ADV MAT I, 1990, THERM SPRAY COAT ALBRIGHT LF, 1978, P ACS 175 NAT M AN C, P175 ALBRIGHT LF, 1978, P ACS 175 NAT M AN C, P205 BECZKOWIAK J, 1989, P 13 ITSC LOND UK, P94 BERNDT CC, 1989, J MATER SCI, V24, P3511 BORBECK KD, 1983, DVS, V80, P99 BOULOS MI, 1985, PURE APPL CHEM, V57, P1321 BOULOS MI, 1989, FUNDAMENTALS MAT PRO, P275 BROWN L, 1986, ADV THERMAL SPRAYING, P507 BRUNET C, 1986, ADV THERMAL SPRAYING, P129 BUCHANAN ER, 1987, TURBOMACH INT, V28, P25 BUTLER EP, 1985, MATER SCI TECH SER, V1, P417 CHAN K, 1987, CERAM IND, V129, P24 CHANDLER PE, 1987, P 2 INT C SURF ENG S, P403 CHANG GC, 1987, SURF COAT TECH, V30, P13 COMASSAR DM, 1991, METAL FINISHING MAR, P39 CURTIS CL, 1993, P 1993 NTSC AN CA JU, P519 CUSHNIE K, 1990, P 3 NTSC THERM SPRAY, P539 DANGELO C, 1988, ADV MAT PROCESSES, V12, P41 DEGROOT K, 1987, J BIOMED MATER RES, V21, P1375 DEGROOT K, 1991, J CERAM SOC JAPAN IN, V99, P917 FESSENDEN KS, 1990, P 3 NTSC THERM SPRAY, P611 FEUERSTEIN A, 1986, P C HIGH TEMP ALL GA, P1227 FILIAGGI MJ, 1991, J BIOMED MATER RES, V25, P1211 FUJI S, 1995, P 14 ITSC 95 KOB MAY, P839 GANSERT D, 1990, P 3 NTSC THERM SPRAY, P517 GAYDA J, 1986, INT J FATIGUE, V8, P217 GITZHOFER F, 1991, T 17 WORKSH CUICAC U GOSSMANN T, 1990, P 3 NTSC THERM SPRAY, P503 HAJMRLE K, 1985, MODERN DEV POWDER ME, V15, P609 HANNOTIAU H, 1988, 1 INT C PLASM SURF E HEBSUR MG, 1986, MATER SCI ENG, V83, P239 HEBSUR MG, 1987, THIN SOLID FILMS, V147, P143 HEIMANN RB, IN PRESS PLASMA SPRA HEIMANN RB, 1990, CAN CERAM QUART, V59, P49 HEIMANN RB, 1990, P 3 NAT THERM SPRAY, P491 HEIMANN RB, 1991, AM CERAM SOC BULL, V70, P1120 HEIMANN RB, 1991, P ADV MAT, V1, P181 HENNE R, 1989, FORSCHGUNSVERBUND SO HENNE R, 1989, P 12 ITSC 89 LOND UK, P175 HENNE R, 1994, P 1 EUR SOL OX FUEL, V2, P617 HERMAN H, 1993, CERAMIC FILMS COATIN, P131 HINTERMANN HE, 1984, J VAC SCI TECHNOL B, V2, P816 HODGE PE, 1980, THIN SOLID FILMS, V73, P447 JASIM KM, 1992, MATER SCI TECH SER, V8, P83 JEITSCHKO W, 1963, MONATSH CHEM, V94, P672 KAJI I, 1991, 2 INT S SOFC NAG JAP, P221 KAMACHI K, 1990, P 3 NTSC THERM SPRAY, P497 KERN H, 1990, DVS, V130, P247 KIRBACH ED, 1989, COMMUNICATION KIRNER K, 1989, SCHWEISSEN SCHNEIDEN, V41, P11 KLEIN CPAT, 1991, J BIOMED MATER RES, V25, P53 KNOTEK O, 1975, J VACUUM SCI TECHNOL, V12 KNOTEK O, 1993, DVS, V152, P138 KOLASKA H, 1989, DIMA, P11 KREYE H, 1986, ADV THERMAL SPRAYING, P121 KURIHARA K, 1988, APPL PHYS LETT, V52, P437 KVERNES I, 1987, MATER SCI ENG, V88, P61 KVERNES I, 1992, POWDER METALL INT, V24, P7 LENLING WJ, 1990, P 3 NTSC THERM SPRAY, P451 LEVINE S, 1979, P 1 C ADV FUEL CAP D LI Z, 1993, P 6 NTSC ASM INT MAT, P343 LIN JHC, 1994, J MATER SCI-MATER M, V5, P279 LONGO FH, 1994, THERMAL SPRAY SOURCE LONGO FN, 1976, P 8 ITSC MIAM SEPT LUGSCHEIDER E, 1986, ADV THERMAL SPRAYING, P137 LUGSCHEIDER E, 1987, P 2 INT C SURF ENG S, P423 LUGSCHEIDER E, 1988, 1 PLASM TECHN S LUC, P55 LUGSCHEIDER E, 1990, P 3 NTSC THERM SPRAY, P635 LUGSCHEIDER E, 1991, POWDER METALL INT, V23, P33 LUGSCHEIDER E, 1992, TECHNICA, V9, P19 LUGSCHEIDER E, 1993, DVS, V152, P82 LUGSCHEIDER E, 1994, J MATER SCI-MATER M, V5, P371 LUGSCHEIDER E, 1995, P 14 ITSC KOB MAY 22, P833 MAIER HR, 1991, TECHNISCHE KERAMIK A, P108 MALLENER W, 1992, P INT THERM SPAR C E, P835 MASH DR, 1961, J METALS JUL, P473 MENNE U, 1993, DVS, V152, P280 MILLER RA, 1984, J AM CERAM SOC, V67, P517 MILLER RA, 1988, 100283 NASA MINAZAWA K, 1991, MHI TECHNICAL B, V28, P41 MUTASIM ZZ, 1990, P 3 NTSC LONG BEACH, P165 NICOLL AR, COATINGS SURFACE TRE, P180 NICOLL AR, 1992, SOFC SEM YOK FEB NICOLL AR, 1994, TECHNICAL REV SULZER, V3, P28 NOTOMI A, 1995, P 14 ITSC KOB MAY 22, P79 OKIAI R, 1989, 1 INT S SOFC NAG JAP, P191 ORTOLANO RJ, 1983, TURBOMACHINERY I APR, P19 PAWLOWSKI L, 1990, P 3 NTSC THERM SPRAY, P641 PAWLOWSKI L, 1995, SCI ENG THERMAL SPRA, P28 PAWLOWSKI L, 1995, SCI ENG THERMAL SPRA, P327 PETITBON A, 1989, MAT SCI ENG A-STRUCT, V121, P545 QURESHI J, 1986, J VAC SCI TECHNOL A, V4, P2638 RANGASWAMY S, 1986, ADV THERMAL SPRAYING, P101 RESTALL JE, 1984, P 5 INT S SUP CHAMP, P721 RHYSJONES TN, 1989, CORROS SCI, V29, P623 RIESENHUBER H, 1989, VAKUUM-TECH, V38, P119 RIVERO DP, 1988, J BIOMED MATER RES, V22, P191 RUCKLE DL, 1980, THIN SOLID FILMS, V73, P455 RUMP H, 1995, KERAM Z, V47, P284 SANDT A, 1986, SCHWEISSEN SCHNEIDEN, V38, P4 SCAGLIOTTI M, 1988, J MATER SCI, V23, P3764 SCHOOP MU, 1917, SCHOOPSCHE METALLSPR SCOTT HG, 1975, J MATER SCI, V10, P1527 SELIVERSTOV NF, 1993, DVS, V152, P442 SHAH A, 1989, P MAT RES SOC S BOST, P747 SHAH A, 1990, APPL PHYS LETT, V57, P1452 SHIMIZU S, 1991, WELDING INT, V5, P1 SIMONS B, 1995, PLATIN SEM INN ANW P SIVAKUMAR R, 1988, SURF COAT TECH, V37, P139 SMITH RW, 1981, J MET, V33, P23 SMITH RW, 1981, T ASME, V103, P146 SMITH RW, 1991, POWDER METALL INT, V23, P147 SMITH RW, 1991, POWDER METALL INT, V23, P231 SMITH RW, 1992, J THERM SPRAY TECHN, V1, P57 SMITH RW, 1993, P 5 NTSC AN CA JUN SOBALLE K, 1993, ACTA ORTHOP SCAND STECURA S, 1982, CERAM B, V61, P256 STRODER U, 1992, WERKSTOFF INNOVATION, V3, P5 STURGEON AJ, 1995, P ITSC 95 KOB, P933 SUMNER WJ, 1985, P AM POW C APR 22 24, P196 SUTLIFF SK, 1987, T 4 WORKSH CUICAC TO SWALES GL, 1980, BEHAV HIGH TEMPERATU, P45 TAI LW, 1991, J AM CERAM SOC, V74, P501 THIELE S, IN PRESS J MAT SCI L TU C, 1985, J VAC SCI TECHNOL A, V3 UCHIYAMA F, 1992, 13 ITSC ORL FLOR MAY, P27 VINAYO ME, 1985, J VAC SCI TECHNOL A, V3, P2483 VU TA, IN PRESS EUROP J MIN VUORISTO P, 1995, P 14 ITSC 95 KOB MAY, P699 WELCH DO, 1987, NATURE, V327, P278 WLODEK ST, 1985, EPRI WORKSH SOL PART WOLKE JGC, 1992, J THERM SPRAY TECHN, V1, P75 WOZNIEWSKI A, 1990, P INT C MET COAT SAN WRIGHT IG, 1986, OXID MET, V25, P175 WRIGHT IG, 1987, MATER SCI ENG, V88, P261 WU BC, 1989, J AM CERAM SOC, V72, P212 YAJIMA H, 1995, P 14 ITSC KOB MAY 22, P621 ZHU H, 1989, P 9 INT S PLASM CHEM, P876 ZHU H, 1991, J APPL PHYS, V65, P3404 ZIMMERMANN C, 1992, THESIS U HEIDELBERG NR 146 TC 15 PU TRANS TECH PUBLICATIONS PI CLAUSTHAL ZELLERFE PA EINERSBERGER BLICK 28, PO BOX 266, W-3392 CLAUSTHAL ZELLERFE, GERMANY SN 1013-9826 J9 KEY ENG MAT PY 1996 VL 122- BP 399 EP 441 PG 43 SC Materials Science, Ceramics; Materials Science, Composites GA BH23G UT ISI:A1996BH23G00020 ER PT J AU Walls, DP deLaneuville, RE Cunningham, SE TI Damage tolerance based life prediction in gas turbine engine blades under vibratory high cycle fatigue SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB A novel fracture mechanics approach has been used to predict crack propagation lives in gas turbine engine blades subjected to vibratory high cycle fatigue (HCF). The vibratory loading included both a resonant mode and a nonresonant mode, with one blade subjected to only the nonresonant mode and another blade to both modes. A life prediction algorithm was utilized to predict HCF propagation lives for each case. The life prediction system incorporates a boundary integral element (BIE) derived hybrid stress intensity solution, which accounts for the transition from a surface crack to corner crack to edge crack. It also includes a derivation of threshold crack length from threshold stress intensity factors to give crack size limits for no propagation. The stress intensity solution was calibrated for crack aspect ratios measured directly from the fracture surfaces. The model demonstrates the ability to correlate predicted missions to failure with values deduced from fractographic analysis. This analysis helps to validate the use of fracture mechanics approaches for assessing damage tolerance in gas turbine engine components subjected to combined steady and vibratory stresses. RP Walls, DP, UNITED TECHNOL PRATT & WHITNEY,ADV LIFE SYST & METHODS,W PALM BEACH,FL 33410. CR CUNINGHAM SE, 1995, 2 S THERM MECH FAT B CUNNINGHAM SE, 1993, CRACK GROWTH LIFE PR, V1 CUNNINGHAM SE, 1994, CRACK GROWTH LIFE PR, V2 DELUCA DP, 1989, HYDROGEN EFFECTS MAT, P603 TELESMAN J, 1989, ENG FRACT MECH, V34, P1183 NR 5 TC 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1997 VL 119 IS 1 BP 143 EP 146 PG 4 SC Engineering, Mechanical GA WH336 UT ISI:A1997WH33600021 ER PT J AU [Anon] TI Rig tests coatings in quest to extend life of turbine blades SO PROFESSIONAL ENGINEERING LA English DT News Item NR 0 TC 0 PU MECHANICAL ENG PUBL LTD PI EDMUNDS PA PO BOX 24, NORTHGATE AVE, BURY ST, EDMUNDS, SUFFOLK, ENGLAND IP32 6BW SN 0953-6639 J9 PROF ENG JI Prof. Eng. PD JAN 15 PY 1997 VL 10 IS 1 BP 44 EP 44 PG 1 SC Engineering, Mechanical GA WD787 UT ISI:A1997WD78700051 ER PT J AU Chen, H Mukherji, D Wahi, RP Chen, W Wever, H TI Deformation behaviour and cyclic life of the alloy IN738LC under creep-fatigue loading SO TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS LA English DT Article ID HEAT-TREATMENT AB The deformation behaviour and cyclic life of a nickel base superalloy IN738LC, which is a widely used blade material in land based gas turbines. has been studied. The alloy was subjected to total strain controlled low cycle fatigue at 1223 K with superimposed periods of constant tensile stress. Microstructural examination of the fractured specimens as well as of those interrupted at different strain levels before fracture was carried out using optical and transmission electron microscopes. The average creep rate during the hold period showed an initial rapid increase with increase in the number of cycles, followed by a period of constant creep rate at higher hold stresses. ora period of slower increase in the creep rate at lower hold stresses. Fatigue life decreased continuously with decreasing hold stress. The deformation behaviour has been attributed to the nature of dislocation structure inherited from the preceeding compressive part of the cycle and directional coarsening/coalescence of the gamma precipitates. C1 HAHN MEITNER INST BERLIN GMBH,D-14109 BERLIN,GERMANY. RP Chen, H, TECH UNIV BERLIN,INST MET FORSCH,HARDENBERGER STR 36,D-10623 BERLIN,GERMANY. CR ANTOLOVICH SD, 1981, METALL TRANS A, V12, P473 CHEN H, IN PRESS Z METALLKD CHEN H, 1993, ASPECTS HIGH TEMPERA, P513 CHEN W, 1991, MECH BEHAV MAT, V6, P649 GABRISCH H, 1994, MAT ADV POWER ENG 2, P1119 JIAO F, 1991, ANISOTROPY LOCALISAT, P447 JIAO F, 1991, MECH BEHAV MAT, V6, P385 LI J, 1993, Z METALLKD, V84, P4 LI J, 1995, ACTA METALL MATER, V43, P507 MALOW T, 1994, Z METALLKD, V85, P9 MARSHALL P, 1983, FATIGUE HIGH TEMPERA, P259 MATHEW MD, 1991, ACTA METALL MATER, V39, P1507 MU Z, 1990, THESIS U STUTTGART S MUKHERJI D, IN PRESS ACTA METALL MUKHERJI D, 1991, ACTA METALL MATER, V39, P1515 RUMI M, 1994, MAT ADV POWER ENG 19, P1165 WAHI RP, 1992, Z METALLKD, V83, P144 WANG Y, IN PRESS Z METALLKD WARING J, 1983, FATIGUE HIGH TEMPERA, P135 NR 19 TC 1 PU INDIAN INST METALS PI CALCUTTA PA METAL HOUSE, PLOT 13/4, BLOCK AQ, SECTOR V, SALT LAKE, CALCUTTA 700 091, INDIA SN 0019-493X J9 TRANS INDIAN INST MET JI Trans. Indian Inst. Met. PD AUG PY 1996 VL 49 IS 4 BP 349 EP 355 PG 7 SC Metallurgy & Metallurgical Engineering GA WB606 UT ISI:A1996WB60600009 ER PT J AU Godovanets, MA Prusakov, BA Lysenko, II TI Regenerative heat treatment of blades of high-temperature nickel alloys SO METAL SCIENCE AND HEAT TREATMENT LA English DT Article AB An analysis of the operation of blades of gas gas turbine engines (GTE) manufactured from cast nicker alloys has made it possible to determine some of the causes of failure in operation, such as changes in the geometric dimensions or degradation of the microstructure. As a rule, the first cause is considered to be decisive. In order to increase the service life of blades partial regenerative repair of them is envisaged. In this case the dimensions of the blades are usually restored without allowing for possible chan;es in their structure, which can have a negative effect on operation after the restoration For this reason, the second cause can become decisive in the reduction of their service life. This work is devoted to investigating the regularities of the degradation of the structure and properties of the material of cast GTE blades made of a high-temperature nickel alloy of the ZhS6U-VI type under operating conditions. A structural criterion determining the operating capacity of the blades and the ultimate level of structural degradation are established. A regenerative heat treatment to he conducted after partial exhaustion of the operating resource accompanied by structural changes that occur within the critical range of the structural criterion is suggested. CR GODOVANETS MA, 1987, STRUCTURE MECH PHYSI, P47 LOZINSKII MG, 1963, THEORY HIGH TEMPERAT, P23 LYSENKO II, 1989, PROTECTIVE COATINGS, P144 TYAPKIN YD, 1976, STRUCTURAL MECH PHAS, P104 NR 4 TC 0 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 0026-0673 J9 METAL SCI HEAT TREAT-ENGL TR JI Met. Sci. Heat Treat. PD MAY-JUN PY 1996 VL 38 IS 5-6 BP 202 EP 206 PG 5 SC Metallurgy & Metallurgical Engineering GA WA586 UT ISI:A1996WA58600003 ER PT J AU Bradshaw, P TI Turbulence modeling with application to turbomachinery SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID BOUNDARY-LAYER INTERACTIONS; GAS-TURBINE COMBUSTORS; FREE-STREAM TURBULENCE; PRESSURE-DRIVEN; MIXING LAYERS; SHEAR LAYERS; DILATATION-DISSIPATION; LONGITUDINAL VORTEX; 2ND-MOMENT CLOSURE; HEAT-TRANSFER AB The prediction of turbulent flows is a nontrivial problem in internal and external aerodynamics and in many other branches of engineering. The problem appears in perhaps its greatest generality in gas turbines, where predictions oi turbine blade temperature are crucial to engine efficiency or life, and predictions of the composition of combustion products is essential in meeting environmental regulations. Therefore it is logical, and hopefully useful, to make turbomachinery problems the theme of a discussion of the current state of turbulence modeling. The present article contains enough background on the physics of turbulence to illuminate the problems of modeling, but it is not a review of turbulence research in general. Topics of current concern which are dealt with in detail include the validity of the 'law of the wall', the universal near-wall scaling which is the foundation of prediction methods for attached flows and the effect of compressibility on turbulence. Copyright (C) 1996 Elsevier Science Ltd. RP Bradshaw, P, STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. CR *STANF U, 1996, ANN RES BRIEFS 1995 ABID R, 1990, AIAA J, V28, P1426 ADAMS EW, 1984, J GAS TURBINES POWER, V106, P142 ANDERSON SD, 1987, AIAA J, V25, P1086 ARCOUMANIS C, 1987, P I MECH ENG, P57 BALDWIN BS, 1978, AIAA78257 BALDWIN BS, 1990, TM102847 NASA BALLAL DR, 1988, J PROPULSION POWER, V4, P385 BANDYOPADHYAY PR, 1992, AIAA J, V30, P1910 BARDINA J, 1983, TF19 STANF U THERM D BARLOW RS, 1988, J FLUID MECH, V191, P137 BELL JH, 1993, J FLUID MECH, V257, P33 BILGER RW, 1989, ANNU REV FLUID MECH, V21, P101 BIRCH SF, 1972, NASA SP, V321, P11 BLAIR MF, 1983, J HEAT TRANS-T ASME, V105, P33 BLAISDELL GA, 1993, J FLUID MECH, V256, P443 BOGDANOFF DW, 1983, AIAA J, V21, P926 BRADSHAW P, 1971, AGARD C P 93 BRADSHAW P, 1974, J FLUID MECH, V63, P449 BRADSHAW P, 1977, ANNU REV FLUID MECH, V9, P33 BRADSHAW P, 1985, J FLUID MECH, V159, P105 BRADSHAW P, 1987, ANNU REV FLUID MECH, V19, P53 BRADSHAW P, 1987, CTRS87 NASA AM STANF, P159 BRADSHAW P, 1993, PHYS FLUIDS A-FLUID, V5, P3305 BRADSHAW P, 1995, P R SOC A, V451, P165 BRADSHAW P, 1996, J FLUIDS ENG, V118, P24 BROADWELL JE, 1991, PHYS FLUIDS A-FLUID, V3, P1193 BROWN GL, 1974, J FLUID MECH 4, V64, P775 BUSSING TRA, 1988, AIAA J, V26, P1070 CASTRO IP, 1984, J FLUID ENG-T ASME, V106, P298 CASTRO IP, 1990, NEAR WALL TURBULENCE, P123 CEBECI T, 1974, ANAL TURBULENT BOUND CEBECI T, 1977, MOMENTUM TRANSFER BO CEBECI T, 1984, PHYSICAL COMPUTATION CHOI KS, 1984, TURBULENCE CHAOTIC P CHOW JS, 1991, INT WAK VORT S WASH CHOW JS, 1995, AIAA J, V33, P1561 CLEMENS NT, 1995, J FLUID MECH, V284, P171 COAKLEY TJ, 1992, AIAA920436 COLEMAN GN, 1991, 8 S TURB SHEAR FLOWS COLEMAN GN, 1995, J FLUID MECH, V205, P159 COLEMAN GN, 1996, AIAA960655 CROW SC, 1968, J FLUID MECH, V33, P1 CUTLER AD, 1993, EXP FLUIDS, V14, P321 CUTLER AD, 1993, EXP FLUIDS, V14, P393 DRIVER DM, 1990, 102211 NASA TM DRIVER DM, 1991, AIAA911787 DURBIN PA, 1991, THEOR COMP FLUID DYN, V3, P1 DURBIN PA, 1992, J FLUID MECH, V242, P349 DURBIN PA, 1993, J FLUID MECH, V249, P465 EIBECK PA, 1987, J HEAT TRANS-T ASME, V109, P16 ELSENAAR A, 1974, 7095 U NLR TR FAVRE A, 1965, J MECANIQUE, V4, P361 FERNANDO EM, 1990, J FLUID MECH, V211, P285 FERNHOLZ H, 1971, ZEIT ANGEW MATH MECH, V51, T146 FERNHOLZ HH, 1981, AGARDOGRAPH, V263 FERZIGER JH, 1990, NEAR WALL TURBULENCE FERZIGER JH, 1996, COMPUTATIONAL METHOD FLETCHER CAJ, 1988, COMPUTATIONAL TECHNI, V1 FU S, 1987, TFD875 UMIST U MANCH FU S, 1988, J FLUIDS ENG, V110, P216 GHOSAL S, 1995, J FLUID MECH, V286, P229 GIBSON MM, 1978, J FLUID MECH, V86, P491 GIBSON MM, 1990, NEAR WALL TURBULENCE, P157 GOEBEL SG, 1991, AIAA J, V29, P538 GOLDSTEIN S, 1972, J MATH PHYS SCI U MA, V6, P225 GUO Y, 1994, NUMERICAL INVESTIGAT, P245 HANCOCK PE, 1983, J FLUID ENG-T ASME, V105, P284 HANCOCK PE, 1989, J FLUID MECH, V205, P45 HANJALIC K, 1972, J FLUID MECH, V52, P609 HONG SK, 1986, AIAA J, V24, P361 HONG SK, 1986, AIAA J, V24, P971 HORSTMAN CC, 1978, AIAA781160 HUANG PG, 1986, THESIS MANCHESTER U HUANG PG, 1994, AIAA J, V32, P735 HUANG PG, 1995, J FLUID MECH, V305, P185 JAYARAM M, 1985, AIAA850299 JAYARAM M, 1985, J FLUID MECH, V175, P343 JOHNSON DA, 1985, AIAA J, V23, P1684 JOHNSON DA, 1990, AIAA J, V28, P2000 JONES WP, 1972, INT J HEAT MASS TRAN, V15, P301 KADER BA, 1972, INT J HEAT MASS TRAN, V15, P2329 KAYS WM, 1993, CONVECTIVE HEAT MASS KLINE SJ, 1982, P 1980 81 AFOSR HTTM, V1 KLINE SJ, 1990, NEAR WALL TURBULENCE, P200 KOUTMOS P, 1991, J PROPUL POWER, V7, P1064 LAUNDER BE, 1971, TMTNA9 IMP COLL MECH LAUNDER BE, 1975, J FLUID MECHANICS 3, V68, P537 LAUNDER BE, 1987, J FLUID MECH, V183, P63 LAUNDER BE, 1989, INT J HEAT FLUID FL, V10, P282 LAUNDER BE, 1995, AERONAUT J, V99, P419 LELE SK, 1994, ANNU REV FLUID MECH, V26, P211 LUMLEY JL, 1978, ADV APPL MECH, V18, P123 MACIEJEWSKI PK, 1990, NEAR WALL TURBULENCE, P640 MANSOUR NN, 1988, J FLUID MECH, V194, P15 MARVIN JG, 1983, ENG TURBULENCE MODEL, V21, P943 MITCHELTREE RA, 1990, AIAA J, V28, P1625 MOIN P, 1990, PHYS FLUIDS A-FLUID, V2, P1846 MORKOVIN MV, 1962, MECANIQUE TURBULENCE, P367 MULLER UR, 1982, J FLUID MECH, V119, P121 OLCMEN SM, 1995, J FLUID MECH, V290, P225 PAPAMOSCHOU D, 1988, J FLUID MECH, V197, P453 PIERCE FJ, 1983, J FLUID ENG-T ASME, V105, P251 POINSOT TJ, 1991, DIRECT SIMULATION TU, P91 POPE SB, 1978, AIAA J, V16, P279 POPE SB, 1987, ANNU REV FLUID MECH, V19, P237 POPE SB, 1990, 23 S INT COMB COMB I, P591 POPE SB, 1991, PHYS FLUIDS A-FLUID, V3, P1947 POPE SB, 1994, ANN REV FLUID MECH, V26 POVINELLI LA, 1992, NASA C PUB PRANDTL L, 1961, L PRANDTL GESAMMELTE, P775 PURTELL LP, 1992, AIAA920435 RISTORCELLI JR, 1995, 922 ICASE RIZK NK, 1991, J PROPUL POWER, V7, P445 RODI W, 1976, Z ANGEW MATH MECH, V56, P219 RODI W, 1988, 3 INT S REF FLOW MOD ROTTA J, 1951, Z PHYS, V129, P547 ROTTA JC, 1951, Z PHYS, V131, P51 SAMIMY M, 1991, 8 S TURB SHEAR FLOWS SARKAR S, 1991, AIAA J, V29, P743 SARKAR S, 1992, TURBULENT SHEAR FLOW, V8, P249 SARKAR S, 1995, J FLUID MECH, V282, P163 SCHWARZ WR, 1994, J FLUID MECH, V272, P183 SCHWARZ WR, 1994, PHYS FLUIDS, V6, P986 SELIG MS, 1990, NEAR WALL TURBULENCE, P190 SETTLES GS, 1993, 177610 NASA CR SHIH TH, 1987, CTRS87 NASA, P191 SHIZAWA T, 1992, AIAA J, V30, P1180 SOTERIOU MC, 1995, PHYS FLUIDS, V7, P2036 SPALART PR, 1994, RECH AEROSPATIALE, V1, P5 SPEZIALE CG, 1991, J FLUID MECH, V227, P245 SPINA EF, 1994, ANNU REV FLUID MECH, V26, P287 STRETCH D, 1990, B ANN PHYS SOC, V35, P2304 TEITEL M, 1993, INT J HEAT MASS TRAN, V36, P1707 THOMAS NH, 1977, J FLUID MECH, V82, P481 TROUVE A, 1991, SIMULATION FLAME TUR, P273 VANDENBERG B, 1975, J FLUID MECH, V70, P127 VANDENBERG B, 1975, J FLUID MECH, V70, P149 VANDRIEST ER, 1956, AERO ENG REV, V15, P15 VANDRIEST ER, 1956, J AERONAUTICAL SCIEN, V23, P1007 VIEGAS JR, 1985, AIAA850180 VIEGAS JR, 1991, AIAA911783 VREMAN AW, 1995, QMWEP1105 QUEEN MAR WESTPHAL RV, 1987, TURBULENT SHEAR FLOW, V5, P266 WILCOX DC, 1988, AIAA J, V26, P1299 WILCOX DC, 1988, AIAA J, V29, P1311 WILCOX DC, 1991, AIAA911785 WILCOX DC, 1992, 5 S NUM PHYS ASP AER WILCOX DC, 1992, AIAA J, V30, P2639 WILCOX DC, 1993, TURBULENCE MODELING WILSON GJ, 1992, AIAA J, V30, P1008 WINTER KG, 1968, 3633 BRIT AER RES CO ZEMAN O, 1990, PHYS FLUIDS A-FLUID, V2, P178 ZEMAN O, 1991, ROLE PRESSURE DILATA, P105 ZEMAN O, 1993, AIAA930897 NR 155 TC 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0376-0421 J9 PROG AEROSP SCI JI Prog. Aeosp. Sci. PD DEC PY 1996 VL 32 IS 6 BP 575 EP 624 PG 50 SC Engineering, Aerospace GA VY237 UT ISI:A1996VY23700002 ER PT J AU Wu, KC DeLaGuardia, R TI The effects of controls on fatigue loads in two-bladed teetered rotor wind turbines SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB This paper presents a quantitative analysis of the fatigue loads in a down wind yaw-controlled, fired pitch, two-bladed teetered-rotor wind turbine using proportional-integral, full-state optimal, and fuzzy logic controllers, Time-domain simulation data is generated using the EASY5x/WT software developed at the University of Texas at EI Paso. The simulation data reveal that the choice of controller type, or the controller dynamics, can play a very important role in the fatigue life of a wind turbine and should be considered early in the design process of the wind turbine. In summary, the fuzzy logic controller is the most robust controller under a wide regime of wind conditions. It provides the best overall performance in terms of power regulation capability and minimum fatigue lends. The optimal controller with a full-state Kalman filter observer provides a satisfactory performance in terms of power regulation capability and loads when the operating condition is close to the design point at which the controller was optimized. It fails to regulate the power output when the actual operating point deviated too far, about 30 percent in our computer simulations, from the designed operating point. The PI controller provided satisfactory performance in power regulation. However, it produced the worst fatigue loads to the wind turbine among the three controllers. RP Wu, KC, UNIV TEXAS,DEPT MECH & IND ENGN,EL PASO,TX 79968. CR BANNANTINE JA, 1990, FUNDAMENTALS METAL F CRAVER WL, 1991, WIND ENERGY 1991, P35 FRANKLIN GF, 1990, DIGITAL CONTROL DYNA FRIEDLAND B, 1996, ADV CONTROL SYSTEM D KLIR GJ, 1995, FUZZY SETS FUZZY LOG, P11 KOSKO B, 1992, NEURAL NETWORKS FUZZ LEITH DJ, 1994, P 1994 16 BWEA EN C SWIFT AHP, 1993, P AM WIND EN ASS C J SWIFT AHP, 1995, WIND ENERGY 1995, P217 WU KC, 1995, WIND ENERGY 1995, P243 WU KC, 1996, IN PRESS J COMPUTERS NR 11 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 228 EP 234 PG 7 SC Energy & Fuels; Engineering, Mechanical GA VV394 UT ISI:A1996VV39400007 ER PT J AU Rybnikov, AI Getsov, LB TI Thermal fatigue resistance of protective coatings for gas turbine blades SO MATERIALS AT HIGH TEMPERATURES LA English DT Article ID DEPOSITION AB Results of the investigation of thermocyclic strength of flat corset-type specimens (hour-glass-shape) (Getsov, L. B. et al., Industr. Lab., 1982, 7, 44)* from nine heat resistant alloys on a nickel base with protective coatings: electron-beam, i.e. single-layer system M-Cr-Al-Y, multilayer, dual-layer, diffusion, slurry and plasma spray coatings are represented. It is shown that the service life of electron-beam coatings is considerably higher than that of the pack cementation and slurry alumosilicide coatings. Dual-layer overlay coatings with an external ceramic layer have the optimum characteristics. Regularities are established for microcrack initiation and propagation in coatings and high-temperature alloys, depending upon the technology of the coating's deposition and test conditions. RP Rybnikov, AI, NPO CKTI,POLZUNOV CENT BOILER & TURBINE INST,ST PETERSBURG 194021,RUSSIA. CR BALDAEV LC, 1988, PHYS CHEM SOLIDS, P122 BEREGOVSKY VV, 1991, SURF COAT TECH, V48, P13 COUTSOURADIS D, 1978, HIGH TEMPERATURE ALL GETSOV LB, 1982, IND LAB+, V7, P44 JUNZ BI, 1980, ENERGOMASHINOSTROJEN, V12, P32 KUZNETSOV VG, 1993, P 9 INT C PLASM PROC MOVCHAN BA, 1994, SURF COAT TECH, V67, P55 PADVA LG, 1992, PROBL MACHINOSTROJEN, V4, P57 RYBNIKOV AI, 1993, ADV MAT PROCESSING T, P2097 NR 9 TC 5 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1995 VL 13 IS 3 BP 125 EP 131 PG 7 SC Materials Science, Multidisciplinary GA VR729 UT ISI:A1995VR72900003 ER PT J AU Dai, XW Ray, A TI Damage-mitigating control of a reusable rocket engine .2. Formulation of an optimal policy SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article ID MECHANICAL SYSTEMS AB This sequence of papers in two parts investigates the feasibility of damage-mitigating control of a reusable rocket engine similar to the Space Shuttle Main Engine (SSME) where the objective is to increase structural durability without any significant loss of performance. To this effect, a fatigue damage model of the turbine blades has been reported in earlier publications, and a creep damage model of the main thrust chamber coolant channel has been formulated and tested in the first part. This paper, which is the second part, synthesizes an optimal policy for open loop control of up-thrust transients of rite rocket engine. Optimization is based on the integrated model of the plant, structural and damage dynamics under the constraints of fatigue and creep damage in the critical components. The results are presented to demonstrate the potential of life extension of reusable rocket engines via damage mitigating control. The concept of damage mitigation, as presented in this paper; is not restricted to control of rocket engines. It can be applied to any system where structural durability is an important issue. RP Dai, XW, PENN STATE UNIV,DEPT MECH ENGN,UNIVERSITY PK,PA 16802. CR BANNANTINE JA, 1990, FUNDAMENTALS METAL F BOLTON VV, 1989, PREDICTION SERVICE L DAI X, 1995, IN PRESS AIAA J PROP DAI X, 1996, ASME J DYNAMIC SYSTE, V118, P401 DOWLING NE, 1983, J ENG MATER-T ASME, V105, P206 FREED AD, 1988, NASA TM100831 GILL PE, 1991, NPSOL VERSION 4 06 LORENZO CF, 1991, CONTROL SYSTEMS JAN, V12, P42 LUENBERGER DG, 1984, LINEAR NONLINEAR PRO PARIS PC, 1963, ASME, V85, P528 RAY A, 1994, 194470 NASA LEW RES RAY A, 1994, AM CONTR C BALT JUN, P3449 RAY A, 1994, J DYN SYST-T ASME, V116, P437 RAY A, 1994, J DYN SYST-T ASME, V116, P448 RAY A, 1994, J PROPUL POWER, V10, P225 RAY A, 1994, SMART MATER STRUCT, V3, P47 RAY A, 1995, 4640 NASA LEW RES CT RYCHLIK I, 1993, FATIGUE FRACT ENG M, V16, P377 SURESH S, 1991, FATIGUE MAT SUTTON GP, 1992, ROCKET PROPULSION EL SWAIN MH, 1990, 767 AGARD VIDYASAGAR M, 1992, NONLINEAR SYSTEMS AN NR 22 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-0434 J9 J DYN SYST MEAS CONTR JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 1996 VL 118 IS 3 BP 409 EP 415 PG 7 SC Automation & Control Systems; Instruments & Instrumentation GA VK047 UT ISI:A1996VK04700002 ER PT J AU Shin, CS TI Continual service reassurance of steam turbine blades SO ENGINEERING FAILURE ANALYSIS LA English DT Article AB This paper describes a practical case of the successful application of fracture mechanics principles to evaluate turbine blade integrity that led to the saving of a considerable sum of money. Cracks up to 24 mm were detected in some steam turbine blades of a nuclear power generating unit after being in operation for one year. New blades were installed. To ensure safety, the regulatory body required these new blades to be reinspected nine months later during the middle of the nuclear fuel cycle. The reinspection dale fell in the peak demand summer season. Owing to a shortage of reserve electricity generating capacity, there were practical difficulties in stopping operation and opening the turbine casing for inspection. A conservative fracture mechanics analysis was carried out to show conclusively that the blades were safe under the current operating conditions. Considering limitations in the resolution of non-destructive inspection, the analysis started from assuming a pre-existing crack. Fatigue crack growth and fracture under different operating conditions were then considered to arrive at a conservative estimate of the blade life. Following reviews and discussion, the regulatory body agreed that reinspection could be postponed to a convenient date. It was estimated that such a postponement helped to save at least 20 million dollars in direct revenue. Extra savings in reserve energy cost and downstream economic advantages due to the avoidance of cutting the electricity supply have not yet been included. Copyright (C) 1996 Elsevier Science Ltd. RP Shin, CS, NATL TAIWAN UNIV,DEPT MECH ENGN,TAIPEI 10617,TAIWAN. CR *MAT RES LAB, 1987, MRL87AC012C BROEK D, 1986, ELEMENTARY ENG FRACT JAO WT, 1986, P 2 ROC ROK JOINT WO, P247 JAO WT, 1988, MRL B RES DEV, V2, P67 LOGSDON WB, 1975, ENG FRACT MECH, V7, P23 NEWMAN JC, 1983, ASTM STP, V791, P1238 PARIS PC, 1972, ASTM STP, V513, P141 SHIN CS, 1990, 780401E00229 NSC SHIN CS, 1990, ENG FRACT MECH, V37, P423 SMITH SM, 1983, STRESS FAMILY, V2, P120 STEPHENS RI, 1976, ASTM STP, V595, P27 TADA H, 1973, STRESS ANAL CRACKS H TAYLOR D, 1985, COMPENDIUM FATIGUE T NR 13 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD JUN PY 1996 VL 3 IS 2 BP 95 EP 102 PG 8 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA UX062 UT ISI:A1996UX06200002 ER PT J AU Ogawa, A Niikura, M Ouchi, C Minikawa, K Yamada, M TI Development and applications of titanium alloy SP-7OO with high formability SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE titanium alloy; SP-700; heat-treatment; microstructure; mechanical properties; superplastic forming; nonaerospace application; sporting goods AB A new beta-rich alpha + beta titanium alloy, SP-700, was designed to improve hot workability and mechanical properties over Ti-6Al-4V alloy. The chemical composition of the alloy is Ti-4.5Al-3V-2Mo-2Fe, and particularly enhanced properties include superplasticity, hardenability, and fatigue strength. Owing to its extremely fine microstructure and low beta-transus temperature, SP-700 is superplastically formable at temperatures below 1073 K without significant increase in flow stress. More advantageously, diffusion bonding is also accomplished around this temperature. The low temperature SPF/DB process not only saves die material life and process costs, but also reduces alloy degradation from exposure al elevated temperatures, e.g., grain growth and oxidation. Isothermal and conventional hot forging are also performed better with SP-700 than ordinary titanium alloys like Ti-6Al-4V. The alloy is heat treatable and one of its many mechanical properties is that high strength over 1200 MPa is attained in solution treatment and aging condition. The advantage to this is that the moderately stable beta phase tolerates air fooling for solution treatment. Thermal distortion in work pieces, which would be caused by rapid cooling, is consequently avoided. In addition, the alloy is cold workable in such cases as rolling and blanking, when annealed around 1073 K. Furthermore, fatigue life and resistance to hydrogen-assisted stress corrosion cracking are improved due to reduced aluminum content. The superior properties of SP-700 over conventional titanium alloys make new applications possible in non-aerospace fields including sporting goods, hand tools, and wrist watches. Golf drivers, with club heads made of SP-700, are sold commercially Crampons, a new product of SP-700, withstand cold blanking and bending which reduces production costs and extends life. Due to its high forgeability, SP-700 is expected to extend its application to the production of steam turbine blades. Details of practical applications have been demonstrated together with advantages of properties and fabrication for the blades. C1 NKK CORP,SPECIALTY STEEL & TITANIUM MKT & SALES DEPT,CHIYODA KU,TOKYO 100,JAPAN. RP Ogawa, A, NKK CORP,MAT & PROC RES CTR,KAWASAKI,KANAGAWA 210,JAPAN. CR *NEW EN IND TECHN, PROJ CO2 FIX UT US C BANIA PJ, 1993, BETA TITANIUM ALLOYS, P3 FUJITA T, 1993, BETA TITANIUM ALLOYS, P297 HORIO Y, 1993, P 3 JAP INT SAMPE S, P78 ISHIKAWA M, 1993, TITANIUM 92 SCI TECH, P141 ITO H, 1984, MHI, V21, P670 KOMATSU K, 1993, TITANIUM ZIRCONIUM, V41, P155 OGAWA A, 1995, 8 TIT C OUCHI C, 1992, NKK TECHNICAL REV, P61 SATO S, 1993, P 3 JAP INT SAMPE S, P1608 WERT JA, 1983, METALL TRANS A, V14, P2535 NR 11 TC 3 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1996 VL 24 IS 2 BP 100 EP 109 PG 10 SC Materials Science, Characterization & Testing GA UM545 UT ISI:A1996UM54500009 ER PT J AU Cheruvu, NS Carr, TJ Dworak, J Coyle, J TI The in-service degradation of corrosion-resistant coatings SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB As part of work to extend the operating life of turbine blades, rainbow testing was performed to evaluate the effects of cooling-hole design modifications and the impact of a top aluminide on M-Cr-Al-Y coating on insevice coating deterioration. Cooling design modifications considered include a camberline-cooling-hole design, a peripheral-cooling-hole design with a turbulated leading-edge hole, and a peripheral-cooling-hole design with all turbulated holes. The results in this article show that a top aluminide coating and peripheral cooling-hole design extend the M-Cr-Al-Y coating's service life. Additionally, the coating-deterioration results are correlated with the beta-NiAl-depleted zone in the coating and the oxide thickness at the cooling-hole surfaces. Variations of coating degradation and cooling-hole surface oxidation among the blades are discussed in terms of estimated service temperatures measured from gamma' particle size. C1 WESTINGHOUSE ELECT CORP,PITTSBURGH,PA 15222. DOW CHEM CO USA,MIDLAND,MI 48674. RP Cheruvu, NS, SW RES INST,6220 CULEBRA RD,SAN ANTONIO,TX 78238. CR AURRECOECHEA JM, 1990, LIFE ASSESSMENT REPA, P165 BECK DG, 1973, 731D9STABLR3 WEST BOONE DH, 1978, INT C MET COAT SAN F CARR TJ, 1989, 89071 TM WEST COLLINS HE, 1974, METALLURGICAL T, V5, P189 SRINIVASAN V, 1995, MATER MANUF PROCESS, V10, P955 SWAMINATHAN VP, 1995, MATER MANUF PROCESS, V10, P867 TAWANCY HM, 1992, SURF COAT TECH, V54, P1 VERMA SK, 1990, LIFE ASSESSMENT REPA, P179 NR 9 TC 8 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT SOC JI JOM-J. Miner. Met. Mater. Soc. PD MAY PY 1996 VL 48 IS 5 BP 34 EP 38 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA UJ633 UT ISI:A1996UJ63300007 ER PT J AU Millwater, HR Wu, YT Cardinal, JW Chell, GG TI Application of advanced probabilistic fracture mechanics to life evaluation of turbine rotor blade attachments SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB This paper describes the application of an advanced probabilistic fracture mechanics computational algorithm with inspection simulation to the probabilistic life assessment of a turbine blade attachment, sometimes referred to as a steeple or fir tree. The life of the steeple is limited by high cycle fatigue. The methodology utilized combines structural finite element analysis, stochastic fatigue crack growth, and crack inspection and repair. The resulting information provides the engineer with an assessment of the probability of failure of the structure as a function of operating time and the effect of the inspection procedure. This information can form the basis of inspection planning and retirement-for-cause decisions. RP Millwater, HR, SW RES INST,MAT & STRUCT DIV,SAN ANTONIO,TX 78222. CR BERENS AP, 1984, AFWALTR844022 CARDINAL JW, 1991, P EPRI STEAM TURB GE LYLE FF, 1991, REMAINING LIFE METHO MILLWATER HR, 1994, AIAA941507 SAXENA A, 1980, J TESTING EVALU 0805 SEXANA A, 1979, ENG FRACTURE MECH, V12 TORNG T, 1992, AIAA922410 WU YT, 1990, AIAA J, V28, P1663 NR 8 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1996 VL 118 IS 2 BP 394 EP 398 PG 5 SC Engineering, Mechanical GA UJ384 UT ISI:A1996UJ38400022 ER PT J AU Rao, JS Vyas, NS TI Determination of blade stresses under constant speed and transient conditions with nonlinear damping SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID FRICTION AB Determination of resonant stresses is an important step in the life estimation of turbomachine blades. Resonance may occur either at a steady operating speed or under transient conditions of operation when the blade passes through a critical speed. Damping plays a significant role in limiting the amplitudes of vibration and stress values. The blade damping mechanism is very complex in nature, because of interfacial slip, material hysteresis, and gas dynamic damping occurring simultaneously. In this paper, a numerical technique to compute the stress response of a turbine blade with nonlinear damping characteristics, during steady and transient operations of the rotor, is presented. Damping is defined as a function of vibratory merle, rotor speed, and strain amplitude. The technique is illustrated by computing the stress levels at resonant rotor speeds for typical operation of a turbomachine. C1 INDIAN INST TECHNOL,DEPT MECH ENGN,KANPUR 208016,UTTAR PRADESH,INDIA. RP Rao, JS, INDIAN INST TECHNOL,DEPT MECH ENGN,NEW DELHI 110016,INDIA. CR CARNEGIE W, 1957, P I MECH ENG, V171, P873 CARNEGIE W, 1967, B MECHANICAL ENG ED, V6, P29 CRAWLEY EF, 1983, ASME, V105, P575 DYM CL, 1973, SOLID MECHANICS VARI GRIFFIN JH, 1984, P VIB CAMP WORKSH LO HAMMONDS TJ, 1982, ELECT DAMPING ITS EF IRRETIER H, 1986, P IFTOMM INT C ROT D, P301 JONES DIG, 1983, VIBRATIONS BLADES BL, P137 LAGNESE TJ, 1983, P SHOCK VIB B US N 4, V53, P19 LAZAN BJ, 1968, DAMPING MATERIALS ME MACBAIN JC, 1984, J VIB ACOUST, V106, P218 OSTACHOWICS W, 1986, COMPUTERS STRUC, P763 PROVIDAKIS CP, 1986, COMPUTERS STRUC, P957 RAO JS, 1986, P IFTOMM INT C ROT D, P269 RAO JS, 1986, P SHOCK VIBR B US NA, V56, P109 RIEGER NF, 1980, RP11852 EPRI RIEGER NF, 1984, P VIB DAMP WORKSH LO, P2 ROARK RJ, 1976, FORMULAS STRESS STRA SINHA A, 1984, J ENG GAS TURB POWER, V106, P65 SRINIVASAN AV, 1983, J ENG GAS TURB POWER, V105, P332 USMANI MAW, 1986, THESIS IIT NEW DELHI VYAS NS, 1986, THESIS IIT NEW DELHI VYAS NS, 1987, P 7 IFTOMM WORLD C S, P697 NR 23 TC 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1996 VL 118 IS 2 BP 424 EP 433 PG 10 SC Engineering, Mechanical GA UJ384 UT ISI:A1996UJ38400027 ER PT J AU Rottger, G Ulm, W TI Modernizing steam turbines for nuclear power plants SO ATW-INTERNATIONALE ZEITSCHRIFT FUR KERNENERGIE LA German DT Article AB Economic and safe operation of nuclear power plants requires steam turbines with high efficiencies. The progress in flow machanics achieved over the past few years has allowed the use of powerful methods of flow calculation in developments of new blading with greatly enhanced efficiencies. Thanks to the latest manufacturing techniques, the newly developed blading systems can be produced at low cost. Next to progress in flow mechanics, also the broadbased use of advanced finite-element calculations resulted in a more thorough grasp of the many problems associated with structural mechanics assessment of steam turbine components. The theoretical methods have been supplemented by comprehensive efforts in fracture mechanics and experimental materials studies, thus helping to create a reliable knowledge base which will help to avoid the dreaded stress corrosion cracking phenomenon in components of steam turbines. The measures introduced to improve operational reliability already in design and manufacture have been supplemented by modern measurement techniques. Thus, e.g., a system for contactless measurements of blade vibrations allows continuous blade monitoring while the steam turbine is in operation. All these advances are being used successfully in upgrading steam turbines for nuclear power plants. The article contains descriptions of the measures taken to increase efficiency, operational reliablility, and service life, and includes a forecast of further improvements to be expected especially in increases in efficiency. A survey of past and planned revamping measures in nuclear power plant turbines confirms the validity of this approach. C1 SIEMENS KWU,ABT DAMPFTURBINEN GRUNDLAGENENTWICKLUNG,D-45473 MULHEIM,GERMANY. RP Rottger, G, SIEMENS KWU,ABT DAMPFTURBINENSERV,D-45473 MULHEIM,GERMANY. CR DAVID W, 1993, INT JOINT POW GEN C DAVID W, 1995, VGB K KORR KORR KRAF GLOGER M, 1992, INT JOINT POW GEN C GLOGER M, 1995, INT JOINT POW GEN C JANSEN M, 1993, 1092 VDI JANSEN M, 1995, 1 EUR C TURB FLUID D OEYNHAUSEN H, 1987, AM POW C CHIC APR WESCHENFELDER KD, 1994, AM POW C CHIC ILL NR 8 TC 1 PU VERLAGSGRP HANDELSBLATT GMBH PI DUSSELDORF PA POSTFACH 10 11 02, D-40002 DUSSELDORF, GERMANY SN 1431-5254 J9 ATW-INT Z KERNENERG JI ATW-Int. Zeit. Kernenerg. PD JAN PY 1996 VL 41 IS 1 BP 29 EP 32 PG 4 SC Nuclear Science & Technology GA UC036 UT ISI:A1996UC03600008 ER PT J AU Getsov, LB Rybnikov, AI Krukovski, PG Kartavova, EC TI De-alloying and fatigue of high temperature alloys used for gas turbine blades SO MATERIALS AT HIGH TEMPERATURES LA English DT Article AB The laws governing high temperature oxidation and de-alloying of high temperature nickel toasted alloys with aluminium content of up to 2% and their effect on the fatigue resistance at high temperatures are investigated. An experimental and calculation procedure to predict the elements distribution curves in the surface layer of blades, implemented by means of an algorithm and a program for solution of direct and inverse diffusion problems under the arbitrary law of temperature changing, with mobile boundary and selected limiting conditions has been developed. With the availability of sufficient data for a given alloy that characterize the diffusion and the influence of de-alloying on the longevity, the procedure allows a prediction of the remaining service life of the gas turbine blades. C1 INST ENGN THERMAL PHYS,KIEV,UKRAINE. RP Getsov, LB, POLZUNOV CENT BOILER & TURBINE INST,CKTI,NPO,ST PETERSBURG 194021,RUSSIA. CR 1978, HEAT RESISTANCE CONS GETSOV LB, STRENGTH MATER, V2, P170 KOLOMIZEV PT, 1991, METALLURGIA KRUKOVSKY PG, 1992, 11 INT FOR MINSK MAY, V9, P120 MARUSI ON, 1976, FIZ KHIM MEKH, V1, P92 PROKOPENKO AV, 1986, STRENGTH MATERIALS, V10 SIMS C, 1974, SUPERALLOYS NR 7 TC 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1995 VL 13 IS 2 BP 81 EP 86 PG 6 SC Materials Science, Multidisciplinary GA UB649 UT ISI:A1995UB64900002 ER PT J AU Eizner, BA Markov, GV Minevich, AA TI Deposition stages and applications of CAE multicomponent coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE cathodic are evaporation; multicomponent coatings; ion cleaning; cathode erosion; structure formation ID VACUUM-ARC; TITANIUM; NITRIDES; TERNARY; WEAR AB This paper concerns the main physical processes in cathodic are plasma deposition of multicomponent coatings by means of composite cathodes. The following processes are investigated: (1) surface cleaning by ion bombardment; (2) erosion of composite cathodes; (3) generation and acceleration of multicomponent ion flows; and (4) coating growth. Also discussed are three applications of industrial technologies: heat-resistant coatings (NiCrAlSiBY) for gas turbines, erosion-resistant coatings (Ti-Si-N) for compressor blades, and wear-resistant coatings ((Ti,Al)N, Al-Si-N) for cutting tools. RP Eizner, BA, BYELARUSSIAN ACAD SCI,INST TECH PHYS,4 ZHODINSKAYA ST,MINSK 220141,BYELARUS. CR AKSYONOV II, 1977, PHYS CHEM MATER TREA, V6, P89 AKSYONOV II, 1979, UKR PHYS J, V24, P515 BEHRISCH R, 1981, SPUTTERING PARTICLE BOXMAN RL, 1986, THIN SOLID FILMS, V139, P41 COAD JP, 1982, P C ION SURF TREATM, P14 COWAN RS, 1992, J PHYS D APPL PHYS, V25, A285 EIZNER BA, UNPUB EIZNER BA, 1989, PHYS CHEM TREAT MATE, P64 EIZNER BA, 1990, ELECT TREAT MATER, V1, P45 EIZNER BA, 1990, ELECT TREAT MATER, V3, P22 EIZNER BA, 1991, ELECT TREAT MATER, P19 EIZNER BA, 1991, ELECT TREAT MATER, V4, P24 EIZNER BA, 1991, P 3 INT S TRENDS NEW, P46 EIZNER BA, 1991, P INT C CORR 91 CINC EIZNER BA, 1991, SURFACE, V8, P150 EIZNER BA, 1992, MATER MANUF PROCESS, V7, P333 EIZNER BA, 1993, 9 INT C PLASM PROC F, P367 EIZNER BA, 1994, THIN FILMS, P60 GAHR KHZ, 1987, MICROSTRUCTURE WEAR GELD PV, 1971, SILICIDES TRANSITION GOTT YV, 1978, INTERACTION PARTICLE HABIG KH, 1993, FRICT WEAR, V14, P688 HATTO PW, 1986, VACUUM, V36, P67 HUTCHINGS IM, 1992, J PHYS D, V25, A212 KNOTEK O, 1987, J VAC SCI TECHNOL 4, V5, P2173 KNOTEK O, 1993, FRICT WEAR, V14, P681 KOFSTAD P, 1966, HIGH TEMPERATURE OXI KRAGELSKY IV, 1965, FRICTION WEAR LAFFERTY JM, 1980, VACUUM ARCS THEORY A MARTIN PJ, 1987, THIN SOLID FILMS, V153, P91 MINEVICH AA, 1991, P INT SEM TRIB 7M RO, P28 MOVCHAN BA, 1969, FIZ MET METALLOVED, V28, P653 MROTCHEK GA, 1989, PROT MET+, V5, P847 MROTCHEK GA, 1991, ELECT TREAT MATER, V5, P14 MROTCHEK GA, 1991, TECHNOLOGY MULTICOMP NAVINSEK B, 1992, MATER MANUF PROCESS, V7, P363 OTSU M, 1989, THIN SOLID FILMS, V181, P351 PUCHKAREV VF, 1994, J PHYS D APPL PHYS, V27, P1214 RICKERBY DS, 1992, MATER MANUF PROCESS, V7, P495 SASAKI J, 1989, J APPL PHYS, V66, P5198 SUBRAMANIAN C, 1993, WEAR, V165, P85 THORNTON JA, 1977, ANNU REV MATER SCI, V7, P239 VANCOILLE E, 1993, WEAR, V165, P41 WIEDEMANN R, 1994, COMMUNICATION 0310 NR 44 TC 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD FEB PY 1996 VL 79 IS 1-3 BP 178 EP 191 PG 14 SC Materials Science, Coatings & Films; Physics, Applied GA UB580 UT ISI:A1996UB58000023 ER PT J AU Totemeier, TC King, JE TI Isothermal fatigue of an aluminide-coated single-crystal superalloy .1. SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID NICKEL-BASE SUPERALLOY; HIGH-TEMPERATURE COATINGS; MECHANICAL-PROPERTIES; ELEVATED-TEMPERATURE; PROTECTIVE COATINGS; TURBINE-BLADES; CRACK-GROWTH; BEHAVIOR; FRACTURE AB The isothermal fatigue behavior of a high-activity aluminide-coated single-crystal superalloy was studied in air at test temperatures of 600 degrees C, 800 degrees C, and 1000 degrees C. Tests were performed using cylindrical specimens under strain control at similar to 0.25 Hz; total strain ranges from 0.5 to 1.6 pet were investigated. At 600 degrees C, crack initiation occurred at brittle coating cracks, which led to a significant reduction in fatigue life compared to the uncoated alloy. Fatigue cracks grew from the brittle coating cracks initially in a stage II manner with a subsequent transition to crystallographic stage I fatigue. At 800 degrees C and 1000 degrees C, the coating failed quickly by a fatigue process due to the drastic reduction in strength above 750 degrees C, the ductile-brittle transition temperature. These cracks were arrested or slowed by oxidation at the coating-substrate interface and only led to a detriment in life relative to the uncoated material for total strain ranges of 1.2 pet and above 800 degrees C. The presence of the coating was beneficial at 800 degrees C for total strain ranges less than 1.2 pet. No effect of the coating was observed at 1000 degrees C. Crack growth in the substrate at 800 degrees C was similar to 600 degrees C; at 1000 degrees C, greater plasticity and oxidation were observed and cracks grew exclusively in a stage II manner. C1 ARGONNE NATL LAB,IDAHO FALLS,ID 83403. ROLLS ROYCE AEROSP GRP,MAT,DERBY DE24 8BJ,ENGLAND. RP Totemeier, TC, UNIV CAMBRIDGE,DEPT MAT SCI & MET,CAMBRIDGE CB2 3QZ,ENGLAND. CR ANTOLOVICH BF, 1992, SUPERALLOYS 1992, P727 BALL A, 1966, ACTA METALL, V14, P1349 CROMPTON JS, 1984, METALL TRANS A, V15, P1711 DEFRESNE A, 1990, MAT SCI ENG A-STRUCT, V129, P55 DIBOINE A, 1990, HIGH TEMPERATURE FRA, P421 FLEURY E, 1993, MAT SCI ENG A-STRUCT, V167, P23 GALE WF, 1992, METALL TRANS A, V23, P2657 GAYDA J, 1988, SUPERALLOYS 1988, P575 GOWARD GW, 1971, OXID MET, V3, P475 GRUNLING HW, 1987, MATER SCI ENG, V88, P177 HANCOCK P, 1990, SURF COAT TECH, V43, P359 KOLKMAN HJ, 1987, MATER SCI ENG, V89, P81 LEVERANT GR, 1969, T TMS AIME, V245, P1167 LEVERANT GR, 1975, METALL T A, V6, P367 MEETHAM GW, 1986, MATER SCI TECH SER, V2, P290 MOM AJA, 1987, MATER SCI ENG, V87, P361 PENNISI FJ, 1981, THIN SOLID FILMS, V84, P49 RHYSJONES TN, 1988, ADV MATER PROCESS, P129 ROOKE DP, 1976, COMPENDIUM STRESS IN, P237 SIVAKUMAR R, 1989, SURF COAT TECH, V37, P139 STRANG A, 1982, HIGH TEMPERATURE ALL, P469 SURESH S, 1991, FATIGUE MATERIALS, V136 TOTEMEIER TC, 1993, MAT SCI ENG A-STRUCT, V169, P19 TOTEMEIER TC, 1994, THESIS U CAMBRIDGE C VEYS JM, 1987, MATER SCI ENG, V88, P253 WELLS CH, 1968, T ASM, V61, P149 WHITLOW GA, 1984, J ENG MATER-T ASME, V106, P43 WOOD MI, 1988, ADV MATER PROCESS, P179 WOOD MI, 1989, SURF COAT TECH, V39, P29 NR 29 TC 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD FEB PY 1996 VL 27 IS 2 BP 353 EP 361 PG 9 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA TU429 UT ISI:A1996TU42900010 ER PT J AU Easley, ML Smyth, JR TI Ceramic gas turbine technology development SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB AlliedSignal Engines is addressing critical concerns slowing the commercialization of structural ceramics in gas turbine engines. These issues include ceramic component reliability, commitment of ceramic suppliers to support production needs, and refinement of ceramic design technologies. The stated goals of the current program are to develop and demonstrate structural ceramic technology that has the potential for extended operation in a gas turbine environment by incorporation in an auxiliary power unit (APU) to support automotive gas turbine development. AlliedSignal Engines changed the ATTAP ceramic engine test bed from the AGT101 automotive engine to the 331-200[CT] APU. The 331-200[CT] first-stage turbine nozzle segments and blades were redesigned using ceramic materials, employing design methods developed during the earlier DOE/NASA-funded Advanced Gas Turbine (AGT) and the ATTAP programs. The ceramic design technologies under development in the present program include design methods for improved resistance to impact and contact damage, assessment of the effects of oxidation and corrosion on ceramic component life, and assessment of the effectiveness of nondestructive evaluation (NDE) and proof testing methods to reliably identify ceramic parts having critical flaws. AlliedSignal made progress in these activities during 1993 ATTAP efforts. Ceramic palls for the 331-200[CT] engine have been fabricated and evaluated in component tests, to verify the design characteristics and assure structural integrity prior to full-up engine testing. Engine testing is currently under way. The work summarized in this paper was funded by the U.S. Dept of Energy (DOE) Office of Transportation Technologies and administered by NASA-Lewis Research Center, under Contract No. DEN3-335. RP Easley, ML, ALLIED SIGNAL AEROSP CO,ALLIED SIGNAL ENGINES,PHOENIX,AZ. CR 1976, CERAMIC GAS TURBINE 1979, CERAMIC COMPONENTS T 1980, ADV GAS TURBINE AGT1 1987, ADV TURBINE TECHNOLO CUCCIO J, 1986, LIFE PREDICTION METH STRANGMAN TE, 1993, 184TH M EL SOC NEW O NR 6 TC 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1995 VL 117 IS 4 BP 783 EP 791 PG 9 SC Engineering, Mechanical GA TT881 UT ISI:A1995TT88100018 ER PT J AU Wood, MI Raynor, D TI Condition assessment techniques for degraded gas turbine superalloy materials SO INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING LA English DT Article DE creep; superalloys; remanent life; X-ray diffraction; stress rupture; extrapolation; strain accumulation ID LIFE PREDICTION AB Direct and indirect methods of quantifying structural damage or residual mechanical properties ha ie been investigated and compared for virgin Nimonic 115 and es-sen ice material from gas turbine blading. Whilst the indirect technique of X-ray diffraction line profile analysis exhibits a significant increase in line width with increasing creep strain, the current level of experimental scatter would need to be reduced for it to be a useful life assessment tool. The direct technique of temperature accelerated stress rupture (isostress) testing is shown to produce data which can be extrapolated to service conditions with confidence and which can be used in an assessment procedure. Stress accelerated rupture testing is demonstrated to give an unduly conservative indication of residual rupture properties at service conditions. RP Wood, MI, ERA TECHNOL LTD,LEATHERHEAD KT22 7SA,SURREY,ENGLAND. CR 1973, NIMONIC ALLOYS DATA, P115 CANE BJ, 1987, INT MATER REV, V32, P241 CASTILLO R, 1986, NICKEL METALLURGY, V2 DYSON BF, 1990, ISIJ INT, V30, P802 GOTO T, 1984, P C CREEP FRACTURE E, P1135 HOFFELNER W, 1986, HIGH TEMPERATURE ALL, P413 JI N, 1992, ICRS 3 RESIDUAL STRE, P1435 KOUL AK, 1994, ADV MATERIALS COATIN, P75 TAIRA S, T JSME, V28, P1325 TAIRA S, 1961, B JSME, V4, P230 WEISS V, 1984, FATIGUE 84, P1151 WILLIAMSON GK, 1953, ACTA METALL, V1, P22 WOOD MI, 1994, MATERIALS ADV POWER, P929 ZAMRIK SY, 1989, NUCL ENG DES, V116, P407 NR 14 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0308-0161 J9 INT J PRESSURE VESSELS PIPING JI Int. J. Pressure Vessels Pip. PY 1996 VL 66 IS 1-3 BP 341 EP 350 PG 10 SC Engineering, Multidisciplinary; Engineering, Mechanical GA TR567 UT ISI:A1996TR56700029 ER PT J AU Yue, ZF Lu, ZZ Zheng, CQ Yin, ZY TI Life study of nickel-based single crystal turbine blades: Viscoplastic crystallographic constitutive behavior SO THEORETICAL AND APPLIED FRACTURE MECHANICS LA English DT Article AB Based an dislocation theory, an anisotropic crystallographic constitutive relation has been developed for nickel-based single crystal superalloys. Octahedral {111}[110], {111}[112] and cubic {100}[110] slip systems are considered. Drag stress and back stress state variables are used to model the local inelastic flow. Results are compared with test data for nickel-based crystal superalloy DD3 at 700 degrees C and 950 degrees C for evaluating the model parameters at these temperatures. The constitutive relation is applied to a finite element program for estimating the strength and life of a nickel-based single crystal turbine blade. C1 NORTHWESTERN POLYTECH UNIV,DEPT MECH ENGN,XIAN 710072,SHAANXI,PEOPLES R CHINA. CR GILMAN JJ, 1966, 5TH P US NAT C APPL, P385 KREMPL E, 1986, MECH MATER, V5, P35 LALL C, 1970, METALL T A, V1, P1323 MILLIGAN WW, 1989, METALL T A, V18, P85 NABARRO FRN, 1979, DISLOCATIONS SOLIDS OHNE N, 1994, JSME INT J, V37, P129 PAIDAR V, 1984, ACTA METALL, V32, P435 YUE ZF, 1993, ACTA AERONAUTICA AST, V14, A556 YUE ZF, 1994, THESIS NW POLYTECHNI YUE ZF, 1995, METALL MATER TRANS A, V26, P1815 NR 10 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8442 J9 THEOR APPL FRACT MECH JI Theor. Appl. Fract. Mech. PD JAN PY 1996 VL 24 IS 2 BP 139 EP 145 PG 7 SC Engineering, Mechanical; Mechanics GA TR225 UT ISI:A1996TR22500004 ER PT J AU Osyka, AS Rybnikov, AI Leontiev, SA Nikitin, NV Malashenko, IS TI Experience with metal ceramic coating in stationary gas turbines SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE metal ceramic coatings; gas turbine units; properties AB The uncooled rotating blades of the high pressure turbine (HPT) and of the low pressure turbine (LPT) of the peak load power gas turbine GT-100 are protected with electron-beam physically vapour deposited CoCrAlY coatings. Owing to low-temperature hot corrosion leakage, corrosion failure is observed. In order to improve the corrosion resistance, yttria stabilized zirconia (YSZ)/CoCrA/Y coatings with a ceramic layer thickness of 50-70 mu m have been developed. The maximum service life of blades with the YSZ/CoCrAlY coatings has exceeded 939 h with 253 starts. Study of the YSZ/CoCrAlY coated blades after different service periods (from 306 to 939 h) showed different conditions of the ceramic layer: without any kind of damage, with small local damage, and with large-area spalling. C1 NPO TSKTI,POLZUNOV CENT BOILER & TURBINE INST,ST PETERSBURG 194021,RUSSIA. LMZ,ST PETERSBURG 195009,RUSSIA. IVANOVO STATE AREA POWER STN,KOMSOMOLSK 155150,RUSSIA. EO PATON ELECT WELDING INST,KIEV 252005,UKRAINE. RP Osyka, AS, GRES 3,ELEKTROGORSK 142530,RUSSIA. CR MALASHENKO IS, 1990, PROBL SPETS ELEKTROM, P53 MOVCHAN BA, 1985, PROBL SPETS ELEKTROM, P34 MOVCHAN BA, 1994, SURF COAT TECH, V67, P55 NAGAZAJ BA, 1990, ASME GT200 PAP, P11 PATON BE, 1987, CREEP STRENGTH CAST, P256 ROODE MV, 1989, ASME GT242 PAP, P23 RYBNIKOV AI, 1990, STRENGTH MATER, P35 RYBNIKOV AI, 1994, SURF COAT TECH, V68, P38 STRANGMAN TE, 1990, J ENG GAS TURB POWER, V112, P531 NR 9 TC 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV PY 1995 VL 76 IS 1-3 BP 86 EP 94 PG 9 SC Materials Science, Coatings & Films; Physics, Applied GA TM179 UT ISI:A1995TM17900015 ER PT J AU KACHANOV, EB PETRUSHIN, NV SVETLOV, IL TI HEAT-RESISTANT EUTECTIC ALLOYS WITH CARBIDE-INTERMETALLIC STRENGTHENING SO METAL SCIENCE AND HEAT TREATMENT LA English DT Article AB Some important characteristics of gas turbine engines (in the first place the thrust and the efficiency) depend on the gas temperature and hence are determined by the service life of the blades. Heat-resistant nickel alloys are used for casting blades that can work at maximum temperatures of 1050 - 1100 degrees C. However, more efficient engines need materials with a higher operating temperature and high-temperature strength. The work concerns the principles of alloying and structure formation of eutectic heat-resistant alloys on a nickel base with carbide acid intermetallic strengthening, Their main mechanical properties at high temperatures are analyzed in comparison with the characteristics of high-temperature single-crystal nickel alloys, and the possibility of using them for casting turbine blades of high-temperature gas-turbine engines is considered. RP KACHANOV, EB, ALL RUSSIAN INST AIRCRAFT MAT,MOSCOW,RUSSIA. CR 1986, SUPERALLOYS, V2 DAMERVAL C, 1986, CONTRIBUTIONS ETUDE FRASIER DJ, 1990, HIGH TEMPERATURE MAT KHAN T, 1978, P C IN SITU COMPOSIT, V111 MEETHAM GW, 1982, METALL MATER TECHNOL, V14, P387 PATON BE, 1987, HIGH TEMPERATURE STR WOODFORD DA, 1977, METALLURGICAL T A, V8, P639 YANG SW, 1981, P NCKU AAS INT S ENG, P1525 NR 8 TC 0 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU 233 SPRING ST, NEW YORK, NY 10013 SN 0026-0673 J9 METAL SCI HEAT TREAT-ENGL TR JI Met. Sci. Heat Treat. PD MAR-APR PY 1995 VL 37 IS 3-4 BP 154 EP 159 PG 6 SC Metallurgy & Metallurgical Engineering GA TH424 UT ISI:A1995TH42400019 ER PT J AU LINIECKI, A HSU, TR LI, W TI FATIGUE-STRENGTH OF ADHESIVE-BONDED ALUMINUM JOINTS SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE BONDED ALUMINUM JOINTS; FATIGUE STRENGTH; WIND ENERGY AB This paper presents a study involving the assessment of strength of bonded joints. Coupon specimens made of 6061-T6 aluminum alloy were used in the fatigue strength testing experiments. Two sharp grooves were cut on each face of the specimen in order to simulate the cracks in the wind turbine blade. Thin patches made of the same material were adhesively bonded to the surface of the specimen, covering the grooves. All coupon specimens with and without patches were tested under oscillating bending load. Parameters such as the thickness of the adhesive material, the peeling strength and stress distribution between layers were investigated. Failures in the form of patch delamination and subsequent structure fracture were recorded and the numbers of loading cycles which caused these failures were determined. Relationships between the applied loads and the fatigue lives of tested specimens were established. On the basis of the experiments and Finite Element Analysis, an easy-to-use method for estimating the fatigue life of a real wind turbine blade was developed. The proposed method can be extended to applications involving patching of other structures subjected to repeated loads. C1 MACHINERY R&D ACAD,CHENGDU,PEOPLES R CHINA. RP LINIECKI, A, SAN JOSE STATE UNIV,DEPT ENGN MECH,SAN JOSE,CA 95192. CR BAKER AA, 1988, BONDED REPAIR AIRCRA BARNES JW, 1994, STATISTICAL ANAL ENG CORNELL RW, 1953, J APPLIED MECHAN SEP, P354 CROSLEY PB, 1991, J TEST EVAL, V19, P24 FAUPEL JH, 1964, ENG DESIGN GOLAND M, 1994, J APPLIED MECHAN MAR, A17 LUBKIN JL, 1956, T ASME, P1213 POOLE P, 1986, AGARD C P POOLE P, 1991, AUG INT C AIRCR DAM, P85 POOLE P, 1991, AUG INT C AIRCR DAM, P85 REEDY ED, 1991, 10TH ASME WIND EN S, V11, P355 ROSE LRF, 1981, INT J SOLIDS STRUCT, V17, P827 ROSE LRF, 1991, AUG P INT C AIRCR DA, P202 NR 13 TC 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD NOV PY 1995 VL 23 IS 6 BP 453 EP 469 PG 17 SC Materials Science, Characterization & Testing GA TE654 UT ISI:A1995TE65400009 ER PT J AU SORENSEN, B TI HISTORY OF, AND RECENT PROGRESS IN, WIND-ENERGY UTILIZATION SO ANNUAL REVIEW OF ENERGY AND THE ENVIRONMENT LA English DT Review DE POWER SYSTEMS; WIND TURBINE HISTORY; ENVIRONMENTAL-IMPACT ASSESSMENT; LIFE-CYCLE ANALYSIS; WIND TURBINE TECHNOLOGY; WIND RESOURCES AB This review presents the current status of wind turbine technology and recent advances in understanding the long history of wind energy, Reasons for the convergence of technological solutions towards a horizontal axis concept with two or three blades are discussed, and the advances in materials science are identified as determinants of the change toward increasing optimum turbine size. The modest environmental impacts of wind turbines are illustrated by recent life-cycle analyses, and the economic incentive structure and power buy-back rates in different countries are invoked to explain the variation in wind technology penetration in countries with similar resource potentials, Finally, the possible future role of wind technology is discussed, based on resource estimates, competing land demands, government commitments and technological trends, including the recent offshore wind farm developments. RP SORENSEN, B, ROSKILDE UNIV CTR,INST 2,POB 260,DK-4000 ROSKILDE,DENMARK. CR 1913, RELATIONS VOYAGES TE, P194 1974, 2 DAN DEP ENV ENV AG 1975, WIND POWER 1 2 PROPO 1976, CONSULTING ENG NOV, P2 1978, 7 DAN DEP EN NEWSL 1981, MOD2 BONN POW ADM PA 1987, WINDSTATS NEWSLETTER 1995, IN PRESS EXTERNALITI ADLER E, 1920, INGENIOREN, V50, P585 ALFREDSSON PH, 1980, 3RD P INT S WIND EN, P469 ALIDRISI, 1154, CITED INDIRECTLY AZARIN B, 1981, SCIENCE, V81, P81 BASS J, 1992, P DTU BWEA WORKSHOP BESSON J, 1578, THEATRE INSTRUMENTS BETZ A, 1919, NACHR GES WISSENS MP, P193 BETZ A, 1920, Z GESAMTE TURBINENWE, V17, P20 BETZ A, 1926, WIND ENERGY ITS EXPL BUILTJES PJH, 1978, WIND ENG, V2, P135 CAVALLO AJ, 1993, RENEWABLE ENERGY SOU, P121 CRAFOORD C, 1975, DM16 U DEP MET REP DARRIEUS GJM, 1931, 1835018, US DECAMP LS, 1960, ANCIENT ENG DIGBY S, 1954, HIST TECHNOLOGY, V1, P735 DRACHMANN AG, 1961, CENTAURUS, V7, P145 DRZEWIECKI S, 1892, B ASS TECHNIQUES MAR, V3, P11 ELLIOTT DL, 1986, DOECH100934 DEP EN R EYRE N, 1995, EXTERNALITIES FUEL C, V6, P3 FORBES RJ, 1954, HIST TECHNOLOGY, V1, P615 FORBES RJ, 1955, STUDIES ANCIENT TECH, V2, P116 FRITSCHE U, 1993, LIFE CYCLE ANAL ENER, P103 FRITZSCHE AF, 1989, RISK ANAL, V9, P565 GODTFREDSEN F, 1993, R662 RIS NATL LAB RI GREGG MC, 1973, SCI AM, V228, P65 GRUBB MJ, 1993, RENEWABLE ENERGY SOU, P157 GWILT, 1860, ARCHITECTURA HERON ALEXANDRIA, 1951, PNEUMATICS HILL D, 1979, BOOK INGENIOUS DEVIC, P222 HILLS R, 1994, POWER WIND HOLLEY W, 1990, EUROPEAN COMMUNITY W, P743 HYYPIA J, 1980, SCI MECH WIN, P41 JUUL J, 1964, 1961 P UN C NEW SOUR, V7, P229 KEAST D, 1978, COO43891 DEP EN REP KOTTAPALLI S, 1978, 2ND P S WIND EN SYST LACOUR P, 1900, EXPT MILL, V1 LEWIS MJT, 1993, HIST TECHNOLOGY, V15, P141 LJUNGGREN S, 1988, ACOUSTIC MEASUREMENT LORENZ N, 1967, 218TP115 WORLD MET O MACQUEEN J, 1983, IEE P A, V130, P574 MADSEN BT, 1994, INGENIOREN 0805, P2 MADSEN BT, 1994, NATURLIG ENERGI SEP, P6 MANNING CJ, 1981, CONCAWE481 REP MEHREN, 1874, MANUEL COSMOGRAPHIE MEYER H, 1994, R770DA RISO NATL LAB MEYNARD B, 1971, PRAIRIES OR, V3, P607 MILBORROW DJ, 1987, 9TH P BWEA C MOLLER T, 1993, VINDSTYRKE JAN, P1 MOLLER T, 1994, NATURLIG ENERGIE SEP, P6 MUSGROVE P, 1978, 2ND P INT S WIND EN NATH N, 1957, WINDMILLS MILL WRIGH, P1 NEWELL RE, 1969, GLOBAL CIRCULATION A, P42 NIELSEN FB, 1980, PLACING WINDMILLS NIELSEN P, 1993, ENERGIEOG MILJODATA, V3, P1 NIELSEN P, 1994, NATURLIG ENERGIE SEP, P14 PETERSEN EL, 1975, 285 RIS NATL LAB REP ROGERS S, 1977, TID28828 DEP EN REP SENGUPTA D, 1978, TID28828 DEP EN SINGER C, 1954, HIST TECHNOLOGY, V1 SINGER C, 1956, HIST TECHNOLOGY, V2 SKRIVER S, 1994, NATURLIG ENERGIE NOV, P12 SMEATON J, 1796, EXPT INQUIRY NATURAL SORENSEN B, 1975, SCIENCE, V189, P255 SORENSEN B, 1976, SCIENCE, V194, P935 SORENSEN B, 1978, 2ND P INT S WIND EN, G1 SORENSEN B, 1978, SOL ENERGY, V20, P321 SORENSEN B, 1979, RENEWABLE ENERGY SORENSEN B, 1981, AM SCI, V89, P500 SORENSEN B, 1981, ENERG POLICY, V9, P51 SORENSEN B, 1981, RENEWABLE SOURCES EN, P98 SORENSEN B, 1986, STUDY WIND DIESEL GA SORENSEN B, 1993, LIFE CYCLE ANAL ENER, P21 SORENSEN B, 1993, P INT C HEAT MASS TR, P516 SORENSEN B, 1994, 9943 DAN TECH COUNC SORENSEN B, 1994, RENEW ENERG, V5, P1270 SPRENGER A, 1841, MEADOWS GOLD MINES G TROEN I, 1989, EUROPEAN WIND ATLAS VANBUSSEL GJW, 1978, M302 U TECH DELFT RE VANWIJK AJM, 1993, RENEWABLE ENERGY RES VANZUYLEN EJ, 1993, COMP FINANCING ARRAN WAILES R, 1954, HIST TECHNOLOGY, V1, P623 WULFF H, 1966, TRADITIONAL CRAFTS P YEN J, 1976, P INT S WIND ENERGY ZOTENBERG H, 1958, CRONIQUES, V3, P628 NR 92 TC 6 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 SN 1056-3466 J9 ANNU REV ENERG ENVIRON JI Annu. Rev. Energ. Environ. PY 1995 VL 20 BP 387 EP 424 PG 38 SC Energy & Fuels; Engineering, Environmental GA TB634 UT ISI:A1995TB63400015 ER PT J AU ALWAR, RS BABU, S TI INELASTIC STRAIN CONCENTRATION IN DIRECTIONALLY SOLIDIFIED MATERIALS SO TRANSACTIONS OF THE CANADIAN SOCIETY FOR MECHANICAL ENGINEERING LA English DT Article AB The application of Directionally Solidified (DS) materials in the construction of hot section parts (blades, vanes) of a gas turbine results in improvement in the engine performance and durability. Inelastic strain, an important parameter in low cycle fatigue (LCF) life prediction methodology, may be evaluated using simplified methods like Neuber's rule and Equivalent Strain Energy Density Hypothesis. The objectives of the present investigation are to examine the validity of these methods in case of DS materials and to demonstrate using numerical methods that the low cycle fatigue life of DS materials is superior to isotropic materials. RP ALWAR, RS, INDIAN INST TECHNOL,DEPT APPL MECH,MADRAS 600036,TAMIL NADU,INDIA. NR 0 TC 1 PU CANADIAN SOC MECH ENG PI EDMONTON PA DEPT MECHANICAL ENGINEERING UNIV OF ALBERTA, EDMONTON AB T6G 2G8, CANADA SN 0315-8977 J9 TRANS CAN SOC MECH ENG JI Trans. Can. Soc. Mech. Eng. PY 1995 VL 19 IS 3 BP 331 EP 346 PG 16 SC Engineering, Mechanical GA TA312 UT ISI:A1995TA31200011 ER PT J AU MASLENKOV, SB LARKIN, VA ZHEBYNEVA, NF TI EFFECT OF REGIMES OF HOT PLASTIC-DEFORMATION ON THE STRUCTURE AND PROPERTIES OF STAMPED BILLETS SO METAL SCIENCE AND HEAT TREATMENT LA English DT Article AB One way of increasing the service life and reliability of gas-turbine engines is to raise the endurance limit of compressor blades by improving the manufacturing technology. The endurance limit of the blades depends on many factors, the most important of which is the structural state of the material for blade billets. A stable, high endurance limit can be attained if the whole complex of technological effects, beginning with the hot deformation and ending with the surface treatment of ready parts, is optimized. The regimes of hot deformation which creates the initial structure mainly determines the endurance limit. In this paper the influence of the regimes of hot deformation on the structure and endurance limit of stamped billets imitating compressor blades is investigated for the KhN45MVTYuBR-ID (EP718-ID) alloy. RP MASLENKOV, SB, ENGINES RES INST,MOSCOW,RUSSIA. NR 0 TC 0 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU 233 SPRING ST, NEW YORK, NY 10013 SN 0026-0673 J9 METAL SCI HEAT TREAT-ENGL TR JI Met. Sci. Heat Treat. PD JAN-FEB PY 1995 VL 37 IS 1-2 BP 25 EP 27 PG 3 SC Metallurgy & Metallurgical Engineering GA RY197 UT ISI:A1995RY19700007 ER PT J AU WOOD, MI TI THE ASSESSMENT OF SERVICE INDUCED DEGRADATION OF NICKEL-BASED SUPERALLOY GAS-TURBINE BLADING SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Residual stress rupture properties have been determined directly for service run gas turbine blades manufactured from forged Nimonic 115, equiaxed cast IN 738LC and directionally solidified PWA 1422. The validity of the isostress rupture extrapolation procedure at service stress levels has been demonstrated (i.e., linear relationship between test temperature and log of rupture life at a given stress). Rupture tests carried out at greater than service stress levels gave a more conservative indication of the residual properties than those conducted at the service stress. The lack of any simple relationship between the microstructures and the residual properties is discussed. C1 ERA TECHNOL LTD,LEATHERHEAD KT22 7SA,SURREY,ENGLAND. CR 1973, NIMONIC ALLOYS DATA BARBOSA A, 1988, SUPERALLOYS 1988, P683 BUCHMAYR B, 1986, HIGH TEMPERATURE ALL, P413 CANE BJ, 1987, INT MATER REV, V32, P241 CASTILLO R, 1976, 25TH P ANN C MET, P261 HOFFELNER W, 1986, HIGH TEMPERATURE ALL, P413 KOUL AK, 1988, METALL TRANS A, V19, P2049 KOUL AK, 1994, ADV MATERIALS COATIN, P75 LAMBERIGTS M, 1986, HIGH TEMPERATURE ALL, P821 PERSSON C, 1992, SUPERALLOYS 1992, P867 WALKER B, 1992, COMMUNICATION WOOD MI, 1994, MATERIALS ADV POWER, P929 WOODFORD DA, 1992, OCT WORKSH DIR COMB NR 13 TC 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 5 BP 903 EP 923 PG 21 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RX375 UT ISI:A1995RX37500003 ER PT J AU KARLSSON, SA PERSSON, C PERSSON, PO TI METALLOGRAPHIC APPROACH TO TURBINE BLADE LIFE TIME PREDICTION SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB An economically optimized and safe utilization of turbine components is of vital importance to both manufacturers and operators of aero and industrial engines. Calculations of design life must take into consideration variations in several factors, such as material properties, manufacturing processes and operational conditions. Adding safety margins into the calculation results, with necessity, in a conservative figure. The calculated life can be confirmed, or unconfirmed, by examination and testing of randomly selected components during maintenance and overhaul. Techniques for these examinations and for evaluation of the results, in terms of life predictions are not yet fully developed. Methodology and practical results are presented, with comments on prospects and limitations. Medium strength, wrought superalloys to modern, highly alloyed cast blades are covered. The life limiting mechanism of the blades in the program is normally creep. Life time extension by rejuvenation has proven successful, both technically and economically. This paper will describe the practical application of this proven metallographic approach to life time prediction and extension. C1 CELSIUS MAT TEKN AB,S-58013 LINKOPING,SWEDEN. CR LINDBLOM Y, COST50 FIN PROGR REP LINDBLOM Y, 1978, P HIGH TEMPERATURE A, P25 LINDBLOM Y, 1979, MAINTENANCE TECHNIQU LINDBLOM Y, 1982, P HIGH TEMPERATURE A, P4 NR 4 TC 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 5 BP 939 EP 953 PG 15 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RX375 UT ISI:A1995RX37500005 ER PT J AU SRINIVASAN, V CHERUVU, NS CARR, TJ OBRIEN, CM TI DEGRADATION OF MCRALY COATING AND SUBSTRATE SUPERALLOY DURING LONG-TERM THERMAL EXPOSURE SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Reliability and service life of hot gas path components of a gas turbine are limited by the degree of coating and substrate material degradation that occurs during service. MCrAlY type coatings and Ni-base alloys are widely used in the industry. In this study, the effect of long term thermal exposure with and without stress an a blade material, U520 and on a MCrAlY coating has been investigated. Microstructural degradation of coating and U520 material are presented as a function of time, temperature and stress. These results are compared with the degradation observed in service-exposed blades. C1 WESTINGHOUSE ELECT CORP,PGBU,ORLANDO,FL 32826. NR 0 TC 8 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 5 BP 955 EP 969 PG 15 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RX375 UT ISI:A1995RX37500006 ER PT J AU SUGITA, Y ITO, M ISOBE, N SAKURAI, S GOLD, CR BLOOMER, TE KAMEDA, J TI DEGRADATION CHARACTERISTICS OF INTERMETALLIC COATING ON NICKEL-BASE SUPERALLOY SUBSTRATE IN GAS-TURBINE BLADE SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article ID SMALL-PUNCH; EMBRITTLEMENT; ALLOYS AB In-service degradation of the mechanical properties (295-1223 K) and microstructure/chemistry in gas turbine blades made of CoNiCrAlY coatings and Rene 80 substrates has been studied by means of a small punch (SP) testing technique and scanning Auger microprobe (SAM). In SP tests, brittle coating cracks continuously and discretely propagated along the radial and tangential directions at 295 K and elevated temperatures, respectively. The ductility of the coating and substrate at 295 K was lowered during long time operation of the blades. The ductile-brittle transition temperature of used coatings was increased by 90 K, compared with that of unused ones while that of the substrate remained unchanged. From SAM analyses of the unused and used blades, it was found that oxidation and S segregation near the coating surface region profoundly occur in-service. The relationship between the mechanical property degradation and microstructural/chemical evolution near the coating surface is presented which serves as a data base for determining the remaining life of gas turbine blades. C1 CHUBU ELECT POWER CO INC,CTR ELECT POWER RES & DEV,NAGOYA,AICHI 458,JAPAN. HITACHI LTD,MECH ENGN RES LAB,HITACHI,IBARAKI 317,JAPAN. IOWA STATE UNIV SCI & TECHNOL,CTR ADV TECHNOL DEV,AMES,IA 50011. CR BAIK JM, 1983, SCRIPTA METALL, V17, P1143 BAIK JM, 1986, ASTM STP, V888, P92 HIRTH JP, 1980, METALL T A, V11, P150 KAMEDA J, 1989, MAT SCI ENG A-STRUCT, V112, P143 KAMEDA J, 1992, J MATER SCI, V27, P983 KAMEDA J, 1994, MATERIALS SCI ENG A, V183, P124 KAMEDA J, 1995, CONTRACT REPORT IOWA LIU CT, 1987, ACTA METALL, V35, P643 MANAHAN MP, 1981, J NUCL MATER, V103, P1545 MAO XY, 1987, J NUCL MATER, V150, P42 RICKERBY DS, 1991, ADV SURFACE COATINGS SEAH MP, 1983, PRACTICAL SURFACE AN, P181 SEHITOGLU H, 1993, ASTM STP, V1186 SUGITA Y, 1995, IN PRESS P INT S MAT VISWANATHAN R, 1990, LIFE ASSESSMENT REPA NR 15 TC 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 5 BP 987 EP 1005 PG 19 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RX375 UT ISI:A1995RX37500008 ER PT J AU AURRECOECHEA, JM HSU, LL KUBARYCH, KG TI FIELD EXPERIENCE OF PLATINUM ALUMINIDE COATED TURBINE-BLADES SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB This paper describes the results obtained from an evaluation of several platinum aluminide coated first stage turbine blades returned from the field. The IN-738LC blades had accumulated from 3,900 to 27,500 service hours in Centaur (1) 50 industrial gas turbine engines, operating in a high temperature oxidizing environment. The coating performance and condition were assessed using optical and electron microscopy. The condition of the coating was correlated to blade operating temperatures, which were estimated using the gamma prime coarsening technique. The degradation mechanism of the coating, remaining coating life, and blade repairability were also addressed. C1 SOLAR TURBINES INC,SAN DIEGO,CA 92101. CR AURRECOECHEA JM, 1990, GAS TURBINE AEROENGI, P1 CONNER JA, 1992, ASME92GT140 PAP, P1 GOWARD GW, 1967, T AM SOC MET, V60, P228 KUBARYCH KG, 1993, 1993 P ASM MAT C PIT, P59 LINDBLAD NR, 1979, GAS TURBINE C EXHIBI, P1 VANROODE M, 1987, GAS TURBINE C EXHIBI, P1 VANROODE M, 1989, GAS TURBINE AEROENGI, P1 WOOD JH, 1982, GAS TURBINE C EXHIBI, P1 NR 8 TC 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 5 BP 1037 EP 1051 PG 15 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RX375 UT ISI:A1995RX37500011 ER PT J AU STANISA, B IVUSIC, V TI EROSION BEHAVIOR AND MECHANISMS FOR STEAM-TURBINE ROTOR BLADES SO WEAR LA English DT Article DE STEAM; EROSION; TURBINE ROTOR BLADES AB The erosion caused by wet steam flow reduces the efficiency of the last stage rotor blades of condensing steam turbines, and makes their service life shorter. To date there has been insufficient data on the erosion process which the steam turbine rotor blades are subject to during the operation, data which could be a basis for development and verification of mathematical models to estimate the service life of eroded rotor blades. This paper reviews the results of many years monitoring and researching of the laws of the erosion process and its mechanism for rotor blades of condensing steam turbines. On the basis of the obtained laws of the rotor blades erosion process and a simplified model their service life is estimated. C1 ENIN KARLOVAC,KARLOVAC,CROATIA. FAC MECH ENGN & NAVAL ARCHITECTURE ZAGREB,ZAGREB,CROATIA. RP STANISA, B, FAC TECH STUDIES RIJEKA,RIJEKA,CROATIA. CR FADDEEV IP, 1982, EROZIJA DETALEJ PARO, P53 KRZYZANOWSKI JA, 1991, EROZIJA LOPATEK TURB, P300 KRZYZANOWSKI JA, 1994, J ENG GAS TURB POWER, V2, P442 PERELMAN RG, 1986, EROZIJA ELEMENTOV PA, P182 POLLARD D, 1983, GEC J SCI TECHNOL, V1, P29 POVAROV OA, 1988, TEPLOENERGETIKA, V4, P66 PREECE CM, 1979, EROSION, P464 RUML Z, 1987, 7 P ELSI C CAMBR STANISA B, 1979, STROJARSTVO, V3, P161 STANISA B, 1985, STROJARSTVO, V5, P301 STANISA B, 1987, 7 P ELSI C CAMBR STANISA B, 1987, ELEKTROPRIVREDO, V9, P357 STANISA B, 1992, BWK, V3, P93 STORCH W, 1990, STROJARSTVO, V3, P195 NR 14 TC 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD AUG PY 1995 VL 186 IS 2 BP 395 EP 400 PG 6 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA RW620 UT ISI:A1995RW62000008 ER PT J AU MARTINMEIZOSO, A MARTINEZESNAOLA, JM FUENTESPEREZ, M TI INTERACTIVE EFFECT OF MULTIPLE CRACK-GROWTH ON FATIGUE SO THEORETICAL AND APPLIED FRACTURE MECHANICS LA English DT Article ID FILMS AB Interaction of multiple cracks are found in mud when drying and crazing, thin film varnishes or coatings of aeroengine turbine blades. A two-dimensional multiple crack interaction model is developed to simulate the growth of interacting parallel surface cracks. Density and the initial distribution of the microcracks are accounted for in analyzing the growth of a crack to a pre-determined length. Analytical predictions are discussed with reference to experimental observations of fatigue cracks on coated turbine blades. Introduction of a large density of similar cracks can enhance the fatigue life of structural components. C1 CEIT,E-20009 SAN SEBASTIAN,SPAIN. UNIV NAVARRA,ESCUELA SUPER INGN IND,E-20080 SAN SEBASTIAN,SPAIN. CR BENTHEM JB, 1973, METHODS ANAL SOLUTIO BOWIE OL, 1973, METHODS ANAL SOLUTIO DELANNAY F, 1991, ACTA METALL MATER, V39, P1061 HARTRANFT RJ, 1973, METHODS ANAL SOLUTIO HU MS, 1989, ACTA METALL, V37, P917 ISIDA M, 1979, T JSME, V45, P303 MARTINEZESNAOLA JM, 1995, ASTM STP, V126 PRESS WH, 1986, NUMERICAL RECIPES AR SIH GC, 1973, HDB STRESS INTENSITY SPIEGEL MR, 1970, MANUAL FORMULAS TABL TRUSTRUM K, 1983, J MATER SCI, V18, P2765 NR 11 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8442 J9 THEOR APPL FRACT MECH JI Theor. Appl. Fract. Mech. PD SEP-OCT PY 1995 VL 23 IS 3 BP 219 EP 233 PG 15 SC Engineering, Mechanical; Mechanics GA RV687 UT ISI:A1995RV68700006 ER PT J AU SAITH, A NORTON, PF PARTHASARATHY, VM TI APPLICATION OF SPSLIFE TO PRELIMINARY DESIGN EVALUATION AND LIFE ASSESSMENT OF CSGT COMPONENTS SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB The Ceramic Stationary Gas Turbine (CSGT) Program has utilized, the SPSLIFE computer code to evaluate the preliminary design of ceramic components. The CSGT program is being performed under the sponsorship of the United States Department of Energy, Office of Industrial Technology, to improve the performance of stationary gas turbines in cogeneration through the selective replacement of hot section components with ceramic parts. Preliminary design evaluation and life assessment results are presented here for the following, components: (1) Stage 1 turbine blade, (2) Stage 1 turbine nozzle, and (3) combustor inner liner. From the results of the analysis, recommendations are made for improving the life and reliability of the components. All designs were developed in Phase I (preliminary, design) of the CSGT program and will be optimized in Phase II (detail design) of the program. C1 SOLAR TURBINES INC,SAN DIEGO,CA 92101. RP SAITH, A, SUNDSTRAND POWER SYST,SAN DIEGO,CA 92123. CR BOMEMISZA T, ASME94GT486 PAP BOMEMISZA T, IN PRESS T ASME NEMETH NN, 1993, ASTM S LIFE PREDICTI QUINN GD, 1993, ASTM S LIFE PREDICTI SOMA T, 1987, ADV CERAMIC MATERIAL, V2 VANROODE M, 1994, ASME94GT313 PAP WEIBULL W, 1951, J APPLIED MECHANICS, V18 WIEDERHOM SM, 1974, FRACTURE MECHANICS C WIEDERHOM SM, 1991, P ANN AUTOMOTIVE TEC NR 9 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1995 VL 117 IS 3 BP 424 EP 431 PG 8 SC Engineering, Mechanical GA RR457 UT ISI:A1995RR45700007 ER PT S AU MORISSEY, AM SCHOLZ, R TI DETERMINATION OF CREEP DAMAGE IN THE ODS SUPERALLOY MA6000 SO ADVANCES IN ENGINEERING MATERIALS SE KEY ENGINEERING MATERIALS LA English DT Article DE ODS ALLOY; CREEP RESTING; METALLOGRAPHY; ULTRASONIC MEASUREMENTS; MICROHARDNESS AB Ni-based superalloys are widely accepted as being suitable candidates for use in the blade sections of gas turbine engines where improvements in high temperature creep resistance properties are possible as a result of a designed microstructure. The intrinsic changes in microstructure and mechanical properties resulting from the process of creep may become a life-limiting factor. The oxide dispersion strengthened (ODS) superalloy MA6000 was subjected to a high temperature creep euvironment at stresses ranging from 150-550MPa and temperatures of 750, 950 and 1050 degrees C. The potential of certain destructive and non-destructive techniques in detecting the resultant creep damage was explored. The microstructural damage was examined by (1) qualitative and quantitative metallography, (2) ultrasonic wave velocity measurements and (3) microhardness indentations. The responses from the different techniques were compared to each other and to results obtained from austenitic and ferritic steels in order to serve as a basis for assessing residual life. C1 COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,INST ADV MAT,I-21020 ISPRA,ITALY. RP MORISSEY, AM, TRINITY COLL DUBLIN,DEPT MECH & MFG ENGN,DUBLIN 2,IRELAND. CR 1985, ASTM E49475 ARZT E, 1990, RES MECH, V31, P399 BENN RC, 1984, 5TH P INT S SUP 1984, P319 HUTCHINSON JW, 1983, ACTA METALL, V13, P1079 JEFFREY CM, 1991, 3RD ANN REP, P249 MORRISSEY AM, 1994, THESIS TRINITY COLLE STAMM H, 1992, EUROPEAN J NONDESTRU, V1, P169 STAMM H, 1993, P INT C BEHAVIOUR DE, P123 VONESTORFF U, 1992, THESIS U AACHEN WILLEMS H, 1993, COST5012 WORK PACK 5, P1 NR 10 TC 0 PU TRANS TECH PUBLICATIONS PI CLAUSTHAL ZELLERFE PA EINERSBERGER BLICK 28, PO BOX 266, W-3392 CLAUSTHAL ZELLERFE, GERMANY SN 0252-1059 J9 KEY ENG MAT PY 1995 VL 99-1 BP 135 EP 141 PG 7 SC Materials Science, Ceramics; Materials Science, Composites GA BD47F UT ISI:A1995BD47F00016 ER PT J AU CHEN, HJ CHEN, WY MUKHERJI, D WAHI, RP WEVER, H TI CYCLIC LIFE OF SUPERALLOY IN738LC UNDER IN-PHASE AND OUT-OF-PHASE THERMOMECHANICAL FATIGUE LOADING SO ZEITSCHRIFT FUR METALLKUNDE LA English DT Article AB The cyclic life of IN738LC, a widely used nickel base superalloy for blades in stationary gas turbines, was investigated under thermo-mechanical fatigue loading using a temperature variation range of 1023 to 1223 K, with temperature variation rate in the range of 6 to 15 K/min. Simple thermo-mechanical cycles with linear sequences corresponding to in-phase (IP) and out-of-phase (OP) tests were performed. Both the IP and OP tests were carried out at different constant mechanical strain ranges varied between 0.8 to 2.0 % and at a constant mechanical strain rate of 10(-5) s(-1). Thermo-mechanical fatigue lives under both test conditions were compared with each other and with those of isothermal LCF tests at a temperature of 1223 K. The results show that the life under thermo-mechanical fatigue is strongly dependent on the nature of the test, i.e. stress controlled or strain controlled. C1 HAHN MEITNER INST BERLIN GMBH,D-14109 BERLIN,GERMANY. RP CHEN, HJ, TECH UNIV BERLIN,INST MET FORSCH,HARDENBERGER STR 36,D-10623 BERLIN,GERMANY. CR CHEN H, 1993, P S ASPECTS HIGH TEM, P513 COFFIN LF, 1953, 53A76 AM SOC MECH EN COOK TS, 1988, STM STP942, P692 EMBLEY GT, 1984, P 1 PARS INT TURB C, P157 JIAO F, 1992, P C LOW CYCLE FATIGU, V3, P298 MATSUDA N, 1986, J SOC MATER SCI JPN, V35, P810 MUKHERJI D, 1991, ACTA METALL MATER, V39, P1515 NITTA A, 1983, P TOKYO INT GAS TURB, P765 NITTA A, 1988, P C HIGH TEMPERATURE, P203 RUSSELL ES, 1986, P C LIFE PREDICTION SAMUELSSON A, 1981, IM1509 SWED I MET RE NR 11 TC 3 PU CARL HANSER VERLAG PI MUNICH PA KOLBERGERSTRASSE 22, POSTFACH 860420, W-8163 MUNICH, GERMANY SN 0044-3093 J9 Z METALLK JI Z. Metallk. PD JUN PY 1995 VL 86 IS 6 BP 423 EP 427 PG 5 SC Metallurgy & Metallurgical Engineering GA RH776 UT ISI:A1995RH77600008 ER PT J AU FAILOR, J TI LASER CLADDING AND INSPECTION FOR LIFE EXTENSION OF TURBINE-BLADES SO MATERIALS EVALUATION LA English DT Article RP FAILOR, J, TEXTRON TURBINE SERV INC,POB 887,BEECO RD,GREER,SC 29652. NR 0 TC 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD MAR PY 1995 VL 53 IS 3 BP 369 EP 370 PG 2 SC Materials Science, Characterization & Testing GA QN792 UT ISI:A1995QN79200002 ER PT J AU KEMPSTER, A CZECH, N TI A NOVEL METHOD FOR REFURBISHING USED HOT SECTION GAS-TURBINE BLADES SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB During the normal operation of a land-based gas turbine, attack will occur of the gas-washed surfaces of the rotating stationary blades in the turbine hot section. This attack and its intensity can be variable depending on the blade's position in the turbine hot section. This attack Mill progressively degrade these gas-washed surfaces even if these surfaces have been previously coated with a protective layer. During the service period of the turbine, it will be necessary to refurbish the blades from the hotter section of the turbine. One of the refurbishment steps will be to provide the blades with a suitable replacement coating to afford protection until the next service period. Conventional refurbishment techniques used to clean the blade surface rely on abrasive cleaning and / or chemical pickling. These processes may be capable of removing superficial oxidation and any residual coating but are not able consistently to remove the substrate material that has suffered from corrosive attack. It is important that this attacked substrate layer be removed completely, otherwise any residual corrosion products, particularly the presence of deeply penetrated sulfides in grain boundaries, could significantly reduce the life of any subsequent coating. The technique described in this paper essentially activates the surface layer of die substrate that is corroded, thus rendering it more easily removed by chemical and physical means. It is possible by this method to remove up to 400 mu m of the substrate material and provided that all the corrosion products are contained within this zone, it is demonstrated how this produces a clean unattacked surface that is necessary for any subsequent welding, brazing, or recoating operation. C1 KWU,SIEMENS AG,TVWTI,W-4330 MULHEIM,GERMANY. RP KEMPSTER, A, DIFFUS ALLOYS LTD,HATFIELD,HERTS,ENGLAND. CR BURGEL R, 1990, APR P INT C LIF ASS CZECH N, 1990, APR P INT C LIF ASS CZECH N, 1991, 91163329, GB DEBLON B, 1985, TURBOMACHINERY I OCT, P28 DURET C, 1982, HIGH TEMPERATURE ALL, P53 GOWARD GW, 1979, SOURCE BOOK MAT ELEV, P369 GOWARD GW, 1988, ASME, V110, P150 LEHNERT G, 1968, 17961750, GE WOOD JW, 1989, ASME89GT239 PAP NR 9 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1995 VL 117 IS 1 BP 166 EP 171 PG 6 SC Engineering, Mechanical GA QF794 UT ISI:A1995QF79400025 ER PT J AU METWALLY, M TABAKOFF, W HAMED, A TI BLADE EROSION IN AUTOMOTIVE GAS-TURBINE ENGINE SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article AB In this work, a study has been conducted to predict blade erosion and surface deterioration of the free power turbine of an automotive gas turbine engine. The blade material erosion model is based on three-dimensional particle trajectory simulations in the three-dimensional turbine flow field. The particle rebound characteristics after surface impacts were determined from experimental measurements of restitution ratios for blade material samples in a particulate flow tunnel. The trajectories provide the spatial distribution of the particle impact parameters over the blade surfaces. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions, is used in the prediction of blade surface erosion based on the trajectory impact data. The results are presented for the three-dimensional particle trajectories through the turbine blade passages, the particle impact locations, blade surface erosion pattern, and the associated erasion parameters. These parameters include impact velocity impact angle, and impact frequency. The data can be used for life prediction and performance deterioration of the automotive engine under investigation. RP METWALLY, M, UNIV CINCINNATI,DEPT AEROSP ENGN & ENGN MECH,CINCINNATI,OH 45221. CR ANGELL PR, 1976, SAE760280 PAP EROGLU H, 1990, J TURBOMACH, V112, P64 HUSSEIN MF, 1973, J AIRCRAFT, V10, P434 KATSANIS T, 1965, NASA TND2809 KATSANIS T, 1977, NASA TND8430, V1 KATSANIS T, 1977, NASA TND8431, V2 KOFSKEY M, 1978, NASA1007 TECHN PAP TABAKOFF W, 1982, 7TH ANN C MAT COAL C TABAKOFF W, 1984, ORNLSUB848962801 US TABAKOFF W, 1986, J TURBOMACH, V108, P298 TABAKOFF W, 1987, J TURBOMACH, V109, P535 TABAKOFF W, 1990, ORNLFMP902 AR TD F 4, P381 TABAKOFF W, 1990, ORNLSUB848962803 US NR 13 TC 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER-T ASME JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1995 VL 117 IS 1 BP 213 EP 219 PG 7 SC Engineering, Mechanical GA QF794 UT ISI:A1995QF79400031 ER EF