cfd analysis of rotating two-bladed flatback wind

SANDIAREPORTSAND2008-1688UnlimitedReleasePrintedApril2008CFDAnalysisofRotatingTwo-BladedFlatbackWindTurbineRotorDavidD.ChaoandC.P.“Case”vanDamPreparedbySandiaNationalLaboratoriesAlbuquerque,NewMexico87185andLivermore,California94550SandiaisamultiprogramlaboratoryoperatedbySandiaCorporation,aLockheedMartinCompany,fortheUnitedStatesDepartmentofEnergy’sNationalNuclearSecurityAdministrationunderContractDE-AC04-94AL85000.Approvedforpublicrelease;furtherdisseminationunlimited.IssuedbySandiaNationalLaboratories,operatedfortheUnitedStatesDepartmentofEnergybySandiaCorporation.NOTICE:ThisreportwaspreparedasanaccountofworksponsoredbyanagencyoftheUnitedStatesGovernment.NeithertheUnitedStatesGovernment,noranyagencythereof,noranyoftheiremployees,noranyoftheircontractors,subcontractors,ortheiremployees,makeanywarranty,expressorimplied,orassumeanylegalliabilityorresponsibilityfortheaccuracy,completeness,orusefulnessofanyinformation,apparatus,product,orprocessdisclosed,orrepresentthatitsusewouldnotinfringeprivatelyownedrights.Referencehereintoanyspecificcommercialproduct,process,orservicebytradename,trademark,manufacturer,orotherwise,doesnotnecessarilyconstituteorimplyitsendorsement,recommendation,orfavoringbytheUnitedStatesGovernment,anyagencythereof,oranyoftheircontractorsorsubcontractors.TheviewsandopinionsexpressedhereindonotnecessarilystateorreflectthoseoftheUnitedStatesGovernment,anyagencythereof,oranyoftheircontractors.PrintedintheUnitedStatesofAmerica.Thisreporthasbeenreproduceddirectlyfromthebestavailablecopy.AvailabletoDOEandDOEcontractorsfromU.S.DepartmentofEnergyOfficeofScientificandTechnicalInformationP.O.Box62OakRidge,TN37831Telephone:[phone]Facsimile:[phone]E-Mail:[e-mail]::[phone]Facsimile:[phone]E-Mail:[e-mail]:=7-4-0#online2SAND2008-1688UnlimitedReleasePrintedApril2008CFDAnalysisofRotatingTwo-BladedFlatbackWindTurbineRotorDavidD.ChaoandC.P.“Case”vanDamDepartmentofMechanicalandAeronauticalEngineeringUniversityofCaliforniaOneShieldsAvenueDavis,CA95616-5294DaleE.Berg,SandiaNationalLaboratoriesTechnicalManagerSandiaContractNo.15890AbstractTheeffectsofmodifyingtheinboardportionoftheNRELPhaseVIrotorusingathickened,flatbackversionoftheS809designairfoilarestudiedusingathree-dimensionalReynolds-averagedNavier-Stokesmethod.Amotivationforusingsuchathickerairfoildesigncoupledwithablunttrailingedgeistoalleviatestructuralconstraintswhilereducingbladeweightandmaintainingthepowerperformanceoftherotor.ThecalculatedresultsforthebaselinePhaseVIrotorarebenchmarkedagainstwindtunnelresultsobtainedat10,7,and5meterspersecond.Thecalculatedresultsforthemodifiedrotorarecomparedagainstthoseofthebaselinerotor.Theresultsofthisstudydemonstratethatathick,flatbackbladeprofileisviableasabridgetoconnectstructuralrequirementswithaerodynamicperformanceindesigningfuturewindturbinerotors.3AcknowledgementsThisprojectwassupportedbyTPICompositesofWarren,RhodeIslandunderContract15890–Revision4withSandiaNationalLaboratories.TheprimarymembersoftheTPIteamwereDerekBerry(PrincipalInvestigator)andSteveNoletofTPI,KevinJacksonofDynamicDesign,MichaelZuteckofMDZConsultingandC.P.(Case)vanDamandhisgraduatestudents(DavidChaoforthisparticulareffort)attheUniversityofCaliforniaatDavis.ThemembersoftheSandiateamwereTomAshwill,DaleBerg(TechnicalManager),DanielLaird,MarkRumsey,HerbertSutherland,PaulVeersandJoseZayas.4TableofContentsAbstract..............................................................................................................................3Acknowledgements...........................................................................................................4TableofContents..............................................................................................................5ListofFigures....................................................................................................................6Introduction.......................................................................................................................9FlowSolverandGridGeneration.................................................................................10RotorConfigurations....................................................................................................11GridGeneration............................................................................................................12ResultsandDiscussion....................................................................................................1210meterspersecond.....................................................................................................137meterspersecond.......................................................................................................155meterspersecond.........