外文翻译--一维多级轴流压缩机性能的解析优化.doc

英文原文Designefficiencyoptimizationofone-dimensionalmulti-stageaxial-flowcompressorAbstractAmodelfortheoptimaldesignofamulti-stagecompressor,assumingafixedconfigurationoftheflow-path,ispresented.Theabsoluteinletandexitanglesoftherotor,theabsoluteexitangleofthestator,andtherelativegasdensitiesattheinletandexitstationsofthestator,ofeverystage,aretakenasthedesignvariables.Analyticalrelationsofthecompressorelementalstageandthemulti-stagecompressorareobtained.Numericalexamplesareprovidedtoillustratetheeffectsofvariousparametersontheoptimalperformanceofthemulti-stagecompressor.2007ElsevierLtd.Allrightsreserved.Keywords:Multi-stageaxial-flowcompressor；Efficiency；Analyticalrelation；Optimization1.IntroductionThedesignoftheaxial-flowcompressorispartiallyanart.Thelackofaccuratepredictioninfluencesthedesignprocess.Untiltoday,therearenomethodscurrentlyavailablethatpermitthepredictionofthevaluesofthesequantitiestoasufficientaccuracyforanewdesign.Someprogresseshasbeenachievedviatheapplicationofnumericaloptimizationtechniquestosingle-andmulti-stageaxial-flowcompressordesign122.Especiallywiththedevelopmentofcomputationalfluid-dynamics(CFD),manymoreaccuratemethodsofcalculatinghavebeenpresentedinmanyreferencesinwhichthetechniquesofCFDhavebeenappliedtotwo-andthree-dimensionaloptimaldesignsofaxial-flowcompressors1720.However,itisstillofworthwhilesignificancetocalculate,usingone-dimensionalflow-theory,theoptimaldesignofcompressors.Boiko23presentedadetailedmathematicalmodelfortheoptimaldesignofsingle-andmulti-stageaxial-flowturbinesbyassuming(i)afixeddistributionofaxialvelocitiesor(ii)afixedflow-pathshape,andobtainedthecorrespondingoptimizedresults.Usingasimilaridea,Chenetal.22presentedamathematicalmodelfortheoptimaldesignofasingle-stageaxial-flowcompressorbyassumingafixeddistributionofaxialvelocities.Inthispaper,amodelfortheoptimaldesignofamulti-stageaxial-flowcompressor,byassumingafixedflowpathshape,ispresented.Theabsoluteinletandexitanglesoftherotor,theabsoluteexitangleofthestator,andtherelativegasdensitiesattheinletandexitstationsofthestator,ofeachstage,aretakenasthedesignvariables.Analyticalrelationsofthecompressorstageareobtained.Numericalexamplesareprovidedtoillustratetheeffectsofvariousparametersontheoptimalperformanceofthemulti-stagecompressor2.Fundamentalequationsforelemental-stagecompressorConsideran-stageaxial-flowcompressorseeFig.1.Fig.2showsthespecificenthalpyspecificentropydiagramofthiscompressor.Foran-stageaxial-flowcompressor,thereare(2n+1)sectionstations.Thestagevelocitytriangleofanintermediatestage(i.e.jthstage)isshowninFig.3.ThecorrespondingspecificenthalpyspecificentropydiagramisshowninFig.4.Theperformancecalculationofmulti-stagecompressorisperformedusingone-dimensionalflowtheory.Theanalysisbeginswiththeenergyandcontinuityequations,andtheaxial-flowvelocitiesoftheworkingfluidandwheelvelocitiesatthedifferentstationsinthecompressorarenotconsideredasconstant,thatis,ijuu,ijcc(ij),whereidenotestheithstationandjdenotesthejthstage.ThemajorassumptionsmadeinthemethodareasfollowsTheworkingfluidflowsstablyrelativetothevanes,statorsandrotors,whichrotateatafixedspeed.Theworkingfluidiscompressible,non-viscousandadiabatic.Themass-flowrateoftheworkingfluidisconstant.Thecompressionprocessishomogeneousintheworkingfluid.Theabsoluteoutletangleoftheworkingfluid,injthstage,isequaltotheabsoluteinletangleoftheworkingfluidin(j+1)thstage.Theeffectsofintakeandoutletpipingareneglected.Thespecificenthalpiesateverystationareasfollowsj*22ji2ji=1/2iihc（1）j*22j+11i2j+1i1/2iihc（2）Thetotalprofilelossesofthejthstagerotorandthestatorarecalculatedasfollows:222rjrj2j-12j-12j12j-12j-12j-12j-1rj/2/2/hwGFuGctgF（3）222rjsj2j2j2j2jsj/2/1/2hcGFctg（4）Whereriisthetotalprofilelosscoefficientofjthstagerotor-bladeandsjisthatofjthstage-statorblade.Fig.1.Flow-pathofan-stageaxial-flowcompressorFig.2.Enthalpyentropydiagramofan-stagecompressorFig.3.VelocitytriangleofanintermediatestageFig.4.Enthalpyentropydiagramofanintermediatestage.Thebladeprofileloss-coefficientsriandsjarefunctionsofparametersoftheworkingfluidandbladegeometry.Theycanbecalculatedusingvariousmethodsandareconsideredtobeconstants.Whenriandsjarefunctionsoftheparametersoftheworkingfluidandbladegeometry,thelosscoefficientscanbecalculatedusingthemethodofRef.24,whichwasemployedanddescribedinRef.21.Theoptimizationproblemcanbesolvedusingtheiterativemethod:(1)First,selecttheoriginalvaluesofriandsjandthencalculatetheparametersofthestage.(2)Secondly,calculatethevaluesofriandsj,andrepeatthefirststepuntilthedifferencesbetweenthecalculatedvaluesandtheoriginalonesaresmallenough.Theworkrequiredbythejthstageisj2ju,2j2j-1u,2j-12j2j2j-12j-12j2j2j-12j-1GGhucucuctguctgFF（5）Theworkrequiredbythejthrotoris:22222j-12j2j2j-1rj22wwuuh（6）Thedegreeofreactionofthejthstagecompressorisdefinedasrjj/hh.Hence,onehasu,2j222a,2j2j2j-1ja,2j2j2j-11112kctgctgkkctgctg（7）Whereu,ik，a,i12kinarethevelocitycoefficients,andtheyaredefinedas:a,ia,ia,111ii/kccFFandu,ii1/kuuTheconstraintconditionscanbeobtainedfromtheenergy-balanceequationfortheone-dimensionalflowj2*22j-112ji2j2j2ji=1/1/20AiihGFctg（8）j22j12j+1i2j+12j12j+1i1/1/20AiihGFctg（9）3.Mathematicalmodelforthebehaviourofthemulti-stagecompressorThecompressionworkrequiredbyeachstageisj1hjn.Thetotalcompressionworkrequiredbythemulti-stagecompressorisncjj=1hh.Thestagnati