高強化柴油機活塞的熱負荷及結(jié)構(gòu)改進.pdf

1、浙江大學碩士學位論文高強化柴油機活塞的熱負荷及結(jié)構(gòu)改進姓名：譚建松申請學位級別：碩士專業(yè)：動力機械及工程指導教師：嚴兆大20000101浙江大學碩士學位論文摘要ABSTRACTThermalloadingresearchoftheheatedpartsisaveryimportantiteminICEdesignationAlotofachievementshavingbeendonebymanyresearcherssuchasthe

2、rmalboundarycondition，thermalstrengthandthermalfatigueevaluationetcInthispaperthetheorybasisofpistonthermalloadingcalculationandtheprecisionofFEcalculationresultofacertainhigh—dutydieselpistonarediscussedAccordingtothere

3、searchresultsinICEthermalloadingmanyyears，anappropriatecalculatingmodelforthepistonhasbeenestablishedTheheatconvectioncoefficientbetweenthepistoncrownandgashasbeenseparatelycalculatedbyusingdifferentexperienceformulasThe

4、syntheticaverageheatconvectioncoefficienthasbeencalculatedbymeansofindicatordiagrammethodAccordingtoheattransfertheoryandfluidturbulenttheorytheheatcorrelationbetweenthepistontopland，ringzone，skirtzoneandthecoolingwater；

5、theringcoolingoillineofpistonandcoolingoil；thepistoncarityandtheoilmisthavebeensetupFirstlythe3DpistonmodelbymeansofIdenssoRwarehasbeenestablishedthenusingtheautomaticcreatingmeshofthissoRwaretocreatethe3DFEpistonmodel，A

6、ftergettingthepreciseboundaryconditionand3Dtemperaturefield，heatfluxwiththeoriginboundaryconditionandmeasuredtemperaturefromexperiment，thethermalstressfield，deformationvalue，compoundstress(thermomechanicalstress)fieldcar

7、lbecalculatedTheresultsprovidedtheessentialdataforanal蜘ngtlledangerouszoneofpistonToreducethethermalloadingofthispiston，threekindsofcoolingstructurehavebeenofferedinthispaperAtlastthermalfatigueevaluatingmethodsofthepist