逆压边界层流动的湍流模式研究（英文）

逆压边界层流动的湍流模式研究（英文）Turbulent Modeling of Boundary Layer Flow under Adverse Pressure GradientIntroduct

逆压边界层流动的湍流模式研究（英文） TurbulentModelingofBoundaryLayerFlowunderAdverse PressureGradient Introduction: Influiddynamics,boundarylayerisathinlayeroffluid adjacenttothesurfaceofasolidobjectwheretheeffectsof viscosityaredominant.Boundarylayerflowcanbeeitherlaminar orturbulent,dependingontheReynoldsnumberoftheflow.In somepracticalengineeringapplicationswithadversepressure gradients,turbulentflowintheboundarylayerismorecommon duetothehigherReynoldsnumber.Theaimofthispaperisto investigatethedifferentturbulentmodelingapproachesof boundarylayerflowunderadversepressuregradient. TurbulentModeling: Turbulentmodelscanbeclassifiedintotwomaincategories, i.e.,ReynoldsAveragedNavierStokes(RANS)equationsandLarge EddySimulation(LES).RANSisoftenusedforengineering applicationswherethecomputationalcostisamajorconcern,asit providesastatisticaldescriptionofturbulenceintermsof time-averagedquantities.Topredicttheturbulencestatistics, RANSequationsrequireclosuremodelstomodeltheReynolds stresses.TherearetwopopularRANSmodels,i.e.,thek-ɛmodel andtheReynoldsstressmodel(RSM). Thek-ɛmodelisthesimplestandmostwidelyusedRANS model.Itassumesanisotropicturbulencewheretheturbulence kineticenergy(k)andthedissipationrate(ɛ)arethemain turbulentvariables.Themodelhastwotransportequationsfork andɛ,andempiricalconstantstoclosethemodel.Thek-ɛmodel canprovideaccuratepredictionsofturbulentboundarylayerflow, butithassomelimitations,suchastheinabilitytocapture anisotropyandnon-equilibriumturbulence. TheRSMisamorecomplexRANSmodelthatsolvesthefull Reynoldsstresstensor.Itcanaccountfortheanisotropyand non-equilibriumeffectsofturbulence.However,theRSMrequires morecomputationalresourcesthanthek-ɛmodelandismore difficulttoimplement. LESisatime-resolvedapproachthatresolvesthelarge-scale