资源描述:
《BLADE LOADING AND ITS APPLICATION IN THE MEAN-LINE DESIGN OF LOW pressure turbine》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、ProceedingsofASMETurboExpo2011GT2011June6-10,2011,Vancouver,BritishColumbia,CanadaGT2011-45238BLADELOADINGANDITSAPPLICATIONINTHEMEAN-LINEDESIGNOFLOWPRESSURETURBINESJohnD.Coull,HowardP.HodsonWhittleLaboratoryUniversityofCambridge,UKABSTRACTdiagramsindicatin
2、gtheapproximateflowanglesandpossibleInordertominimizethenumberofiterationstoaturbinebladeshapeshavebeenadded.design,reasonablechoicesofthekeyparametersmustbemadeAstheflowcoefficientisincreased(movingfromtheattheearliestpossibleopportunity.Thechoiceofbladel
3、oadingbottomlefttothebottomrightofFig.1),thethrough-flowisofparticularconcerninthelowpressure(LP)turbineofcivilvelocitiesincreaserelativetothebladespeedastheflowaeroengines,wheretheuseofhigh-liftbladesiswidespread.becomesmoreaxial.Foragivenchangeintangenti
4、alvelocity,Thispaperpresentsananalyticalmean-linedesignstudythiscausesanincreaseinthedynamicpressureswhichtendstoforarepeating-stage,axial-flowLowPressure(LP)turbine.increasethelosses.Furthermore,lossesincreasebecausethereTheproblemofhowtomeasurebladeloadi
5、ngisfirstisasmalleroverallaccelerationthroughthebladerow.Suchaddressed.TheanalysisdemonstratesthattheZweifelaccelerationisbeneficialasittendstominimizethegrowthofcoefficient[1]isnotareasonablegaugeofbladeloadingtheboundarylayersandsecondaryflows.becauseiti
6、nherentlydependsontheflowangles.AmoreAsthestageloadingcoefficientisincreased(movingfromappropriatecoefficientbasedonbladecirculationisproposed.thebottomlefttothetopleftofFig.1),thechangeinwhirlWithoutalargesetofturbinetestdataitisnotpossibletovelocityacros
7、sthebladerowbecomeslarger.Toachievethisdirectlyevaluatetheaccuracyofaparticularlosscorrelation.additionalturningonemusteitheremploybladeswithhigherTheanalysisthereforefocusesontheefficiencytrendswithcirculation(loading),ordecreasethepitch(whilemaintainingr
8、especttoflowcoefficient,stageloading,liftcoefficientandcirculation).Bothtendtoincreaseloss,asdoesthehighexitReynoldsnumber.Ofthevariouslosscorrelationsexamined,flowanglefromthesedesigns(seeequation(14)below).