determinedmeansys.com

www.
ansys.
comANSYSAdvantage2009ANSYS,Inc.
DesigningforQualitySimulationpairedwithoptimizationhelpseliminatecompressorbladefailure.
PowerSystemsManufacturing(PSM)isaglobalproviderofaftermarketgasturbinecomponentsintheindustrialpowergenerationindustry.
Thecompany'sproductlineincludesstationaryandrotatingairfoilcomponents,low-emissioncombustionsystems,andadvancedcomponentsforGEFrames6,7and9andSiemens501F-classmachines.
Inonespecificredesigncase,anoriginalequipmentmanufacturer(OEM)first-stagecompressorbladedesignforapopularlargegasturbineusedforgeneratingelectricitywasnotreachingitsexpectedlife.
Fieldfailurescenariosincludedbladebreakageresultinginconsiderabledownstreamdamage.
Companiesrunningtheseenginesthenhadtoshutthemdownforlengthyperiodswhilemakingrepairs,losingtherevenuefromtheelectricitythattheengineswouldnormallygenerate.
"Severalofourcustomerswererunningintothesameproblemwiththiscompressorbladeandaskedusifwecouldimproveandfixtheissue,"saidPageStrohl,formerleadstructuresengineerforPSM.
"Anynewdesignthatwedevelopedhadtofitintoexactlythesameenvelopeandtohavethesameaerodynamicsastheoriginalblades.
"PSMdesignersandengineersworkedtogethertomodelandsimulatetheoriginalbladedesign,takingintoaccounttheaerodynamicandcentrifugalloads.
Usingsimulation,PSMlocatedthehigheststaticstressesintheblade.
Inaddition,PSMengineersdeterminedthatthebladedesignhadseveralvibratorymodesthatwereexcitedduringengineoperationthatwhencoupledwiththestaticstressescouldresultinfailure.
PSM'sanalysespredictedCADmodelofredesignedcompressorbladeClose-upofthemaximumprincipalstressonthepressuresideof(a)theoriginalequipmentmanufacturer'sand(b)theredesignedbladesabTURBOMACHINERYANSYSAdvantageVolumeIII,Issue2,2009TURBOMACHINERYwww.
ansys.
com9thatthebladewouldfailintheexactlocationsatwhichfailuresoccurredinthefield.
UsingtheANSYSDesignXplorertooltostudyarangeofdesignvariations,Strohldefinedthebladeparametershewantedtovary,assignedacceptableparameterranges,andidentifiedthevariableshewantedtooptimize,whichinthiscasewerebladenaturalfrequenciesandpeaksteadystressesatseverallocationsontheblade.
Basedonthepeakstresslocations,designspacedefinitionswerecreated.
ANSYSDesignXplorersoftwareredefinedtheCADmodelandgeneratedtheseriesofdesignvariationsneededtocarryoutexperimentsfortheentirerangeofparameters.
StrohlthenusedtheANSYSWorkbenchenvironmenttomesheachofthesedesigns,solvethemodels,capturetheresultsandperformthestatisticalanalysesneededtoidentifytheoptimaldesign.
OnceStrohlidentifiedanYou'dbeenalong-timeuserofthetraditionalANSYSMechanicalinterface.
DidyouhaveanyhesitancetransitioningtotheANSYSWorkbenchplatformIfoundithardtoputdownsomethingthatIwasalreadycomfortableandproficientwithinordertostartusingsome-thingcompletelynew.
Itwasn'tuntilIattendedan"IntrotoANSYSWorkbench"trainingthatIattemptedtoreallyutilizeit.
Whenthiscompressorbladeanalysiscameupandwewerefacedwithatimecrunch,IknewIcouldsavetimebytakingadvantageoftheconnectivitytoPro/ENGINEERandthefactthattheactualcomponentsettingsstaywiththemodelasitispassedfromtheCADenvironmenttoANSYSWorkbench.
Byusingthisapproach,thelongleadtasksbecametheCADmodelingandtheaerodynamicanalysisefforts,notthestructuralanalysis-specificones.
Geometryoforiginalequipmentdesign(a)andmodifiedgeometry(b),ascreatedusingANSYSDesignXplorersoftwareHasusingANSYSWorkbenchchangedhowyouapproachsomeofyourprojectsIfindthatIlookforprojectsthatcantakeadvantageoftheease-of-usebenefitsthatANSYSWorkbenchoffers.
PSMrecentlystartedamajorredesignofanothercompressorair-foilandwejumpedrightintoANSYSWorkbenchandANSYSDesignXplorerforit.
Icreatedthebaselinemodelandshowedtheaerodynamicisthowtoduplicateit,regenerateamodifiedPro/ENGINEERmodel,thensolveandchecktheresults.
Iactuallygavemyworkaway.
HowdidthisnewprocessworkItwasveryeasytoperformthesimulation—agreatbenefitofANSYSWorkbench.
Ifthegeometryhadproblemsreadinginordidn'tpassallofthebuilt-inchecks,Iwouldslidemychairovertotheaerodyamicist'sworkstationandtakeaminuteorsoandfixthings.
ItwasreallyabenefitinthatIwasabletodootherworkwhilewewereintheiterativephaseofthedesign.
I,likemany,amworkload-challengedthesedays,andANSYSWorkbenchhelpedtorelievemeofthatparticulartask.
Fromalargerprojectperspective,itgavetheaeroguyagoodlookatalltheitemsthatneededtobereviewedoutsideofhisaeroworld.
Severalofmycoworkersjokewithmethatmyjobconsistspurelyofclickingthemousebuttononeortwotimesforananalysisjob;theysaythatthehardonesarewhenIhavetoclickthemousethreetimes.
Therealtrickinthiscasewassettinguptheoriginalbaselinemodel.
OnceIdidthatcorrectly,itwasapieceofcaketohavesomeoneelseturntheanalysisaroundwithANSYSWorkbench.
optimaldesign,theaerodynamicsteammademinordesignmodificationsinordertoensurethatthedesignperformedaerodynamicallyasrequired.
Theresultingdesignreducedallpeaksteadystresses.
Thevibrationalissueswereeliminatedaswellwiththesedesignmodifications.
ThebladesareperformingasexpectedandhavebeeninoperationsinceMay2008.
Additionalsetsarenowonorder.
Strohlconcluded,"KeytotheseimprovementswastheabilityoftheANSYSWorkbenchplatformtointerfacewithourCADsystem,allowingustoquicklypreparenewgeometriesforanalysisandtocontroltheCADsystemtoexploreadesignspace.
Wewereabletoquicklyiteratetoadesignthatwasoptimal,allwhilemaintainingthesameaerodynamicpropertiesastheoriginaldesign.
"sTransitioningintotheANSYSWorkbenchEnvironmentabANSYSAdvantageeditorstalkedtoJ.
PageStrohl,formerLeadStructuresEngineerforPowerSystemsManufacturinginFlorida,U.
S.
A.
,abouthischallengesinredesigningbladesforturbomachinery.