STARCCM實例操作教程鳳洞仿真

WORKSHOP:TheSTAR-CCM+workflow43IntroducesthemainprocessesinSTAR-CCM+CarinawindtunnelObjective:

FollowthroughallthestagesintheSTAR-CCM+workflow.GainconfidenceinusingtheSTAR-CCM+interface.Thisexerciseusesasimplegeometryofacarinawindtunnel.Laterexerciseswillbuildonthebasicslearnthere.44WorkflowforasimplecarFeaturescovered:Import.x_tgeometryofsurface.Nosurfacerepairrequired.Splitsurfacestodefinerequiredboundaries.Definemeshsettings.Specifythicknessofprismlayer.Definephysicssettings.Incompressible,turbulent,steady.Checksolversettings.Usedefaults.Runsimulation.Postprocessingiscoveredinnextexercise!45ImportGeometryPreparationBoundaryConditionsMeshingPhysicsSolverSettingsPostProcessingStartaSTAR-CCM+simulationLaunchSTAR-CCM+.StartanewsimulationbygoingtoFile>NewSimulation…KeepthedefaultsettingsinthedialogueboxandclickonOK.46ImportBoundaryConditionsImportgeometryFile>Import>ImportSurfaceMeshandchoosethesurfacenamedWorkflow/wind_tunnel.x_t.SelecttoCreateNewPart,leaveremainingoptionsattheirdefaultvaluesandclickOKintheImportSurfaceOptions

dialog.47ImportBoundaryConditionsImportGeometryTheimportshowsonegeometrypart,containingonesurface.Inthescene/plotpanelselectGeometryScene1>Displayers>Geometry1.InthePropertiespanel,turnontheMeshdisplayoption.Geometryandscalardisplayersalsochangebyusingthescenetoolbar’sactivatemeshbutton.Savethefileaswind_tunnel.sim.48CheckSurfaceCheckthesurfaceforerrors.Gotothesimulationtree.Right-clickonGeometry>Parts>wind_tunnel>RepairSurface...ClickOKintheopeningwindow.49CheckSurfaceIntheeditpanelclickonManageThresholds.Inthenewpanelcheckthatallthresholdsareactive,thenclickApplyandOK.50CheckSurfaceTherearenograveerrorsinthegeometry,closethepanelaftercheckingthem.TheCloseProximityFacesareresolvedaftersplittingandinterfacecreation.PoorQualityFacesaregoneafterremeshing.51ScalingandSplittingWeneedtoscaletheimportbyafactorof10tochangethelengthtometers.Select

Geometry>Parts>wind_tunnelnode.RightclickandselectTransform>Scalefromcontextmenu.InthedialogboxenteraScaleFactorof10.ClickApplyandClose.ClickontheResetViewicon.Splittheimportedsurfacestoassigntoindividualboundaries.SelecttheGeometry>Parts>wind_tunnel>Surfaces>Facesnode.RightclickandselectSplitbyPatch...fromthecontextmenu.52ImportBoundaryConditionsSpecifygeometrysetupSplitandrenamethePartSurfaces.Clickthefrontfaceoftheairflowinthewindtunnel,renameittoInletandclickCreate.Dothesamefortheotherfaces:Thesymmetryface SymmetryThesideface WallThebackface OutletThebottomface FloorThetopface TopClickClose.53InletWallTopSymmetryFloorOutletGeometryPreparationBoundaryConditionsSpecifygeometrysetupSplitthecarintoseparatesurfacestoo.RightclickonFacesandselectSplitNon-Contiguousfromcontextmenu.Clickonthenamesofthethreenewlycreatedsurfacestohighlighttheirgeometryinthescene.SelectthetwowheelsusingCTRL,thenrightclickandselectCombinetogatherthemunderthesameboundary.RenamethewheelsasWheelsandthecarasBody.54GeometryPreparationBoundaryConditionsTransferofgeometryelementsSTAR-CCM+separatesgeometrypartsfromsimulationrelevantregions.Simulationrelevantpartsneedtobetransferredintotheregionsfolder.Selectwind_tunnel>AssignPartstoRegions…Modes:Oneregionperpart.Oneboundaryperpartsurface.ClickCreateRegions

andClose.55GeometryPreparationBoundaryConditionsDefineboundaryconditionsTheboundarytypeaffectsthemeshing.GotoRegions.SelecteachboundaryandsetitsTypeinthePropertieswindowfollowingthetablebelow.56BoundaryConditionsBoundaryConditionsBoundaryTypeFloor,Top,Wall,Body,WheelsWallInletVelocityInletOutletPressureOutletSymmetrySymmetryPlaneMeshingBoundaryConditionsSelectmeshmodelsSelectthemeshingmodels,STAR-CCM+loadsadditionalfunctionalityonlyifrequired.GotoParts>wind_tunnel.RightclickandselectCreateMeshOperation>AutomatedMesh.Checkthatwind_tunnelisselectedforPartsandselectthemodels:SurfaceRemesher.TrimmedCellMesher.PrismLayerMesher.ClickOK.AnewentryappearsunderOperations.Theyellowexclamationmarkindicatesthatthisoperationhasnotbeenexecutedyet.57MeshingBoundaryConditionsDefaultmeshsettingsMakethedefaultmeshsettings.GotoOperations>AutomatedMesh.UnderDefaultControlsset:BaseSize:0.25m.PrismLayerTotalThickness>RelativeSize:10%.58MeshingBoundaryConditionsGeneratemeshStartthemeshingpipeline.GotoOperations>AutomatedMesh.RightclickandselectExecute.OrpresstheGenerateVolumeMeshbuttoninthetoolbar.STAR-CCM+automaticallygeneratesasurfacemesh,thenavolumemeshwithprismlayersonthewalls.TheexclamationmarkdisappearsandanewnodeisaddedtoContinua:PartsMeshes.59MeshingBoundaryConditionsGeneratemeshInanewscenethemeshisvisualized.Createanewmeshscene.RightclickontheScenes>NewScene>Mesh.OrusetheCreate/OpenScenesbuttoninthevistoolbar:Makethescenetransparent.60VisualizeMeshChangetheview.PressTonyourkeyboard.ThisisashortcutforTopviewinz-direction.Makeviewparallel.Clickonthecameraicon.SelectProjection>Parallel.Createasectionplanethroughthewheels.Inthevistoolbarclickonthefxicon.Drawalineinthesceneasshowninthepicture.ChoosetoselectaNewGeometryDisplayer.61VisualizeMeshChangethepositionofthesectionplaneifitdoesn'tcutthroughthewheel.GotoDerivedParts>planesection.InthepropertieswindowofSinglesectionclickontheOffset

value.Asliderappearsandallowstoadjustthepositioninteractively.62VisualizeMeshHidedisplayerMesh1.Gotothescene/plotpanel.RightclickDisplayers>Mesh1>ToggleVisibility.MakemeshvisiblefordisplayerSectionGeometry1.ClickonDisplayers>SectionGeometry1.InthepropertieswindowclickontheMeshcheckbox.ExpandtheSectionGeometry1>Partsfolder.Rightclickplanesection>AlignViewtoPartNormal.63PhysicsBoundaryConditionsSettingthephysicsChoosethephysicsmodels.RightclickonPhysics1undertheContinuanode.ChooseSelectmodels...InthePhysicsModelSelectiondialog,select:Steady,Gas,SegregatedFlow,IdealGas,SegregatedFluidTemperature,Turbulent,K-EpsilonTurbulence,CellQualityRemediation.64SettingthesimulationconditionsWewanttosetanairflowvelocityinthewindtunnelof15m/s.GotoRegions>wind_tunnel.OpenfolderBoundaries>Inlet>PhysicsValues>VelocityMagnitude.ClickonConstant

andsetthevelocityvalueto15m/sintheProperties

window.65PhysicsBoundaryConditionsSolverSettingsBoundaryConditionsSettingthestoppingcriteriaDecreasethemaximumsteps.GotoStoppingCriteria.SetMaximumStepsto200(350iftimeallowsit)intheProperties

window.66PostProcessingBoundaryConditionsPostprocessingViewthepressurefieldwhilethesolutionisrunning.Createanewscalarscene.Gotothescene/plotpanelandclickonthefollowingentriesofDisplayers>Scalar1.ChangethesettingsinthePropertieswindow.Scalar1:ContourStyle–SmoothFilled.Partsfolder:SelectRegions>wind_tunnel>Body,SymmetryandWheels.ScalarField:Function–Pressure.67RunningRunthesimulationuntilthestoppingcriterionisreached.Arrangetheresidualplotandscalarscenesothatbotharevisible.ClickontheRunbuttononthetopofthetoolbar:Savesimulationaftertherunhasstopped.Theflowsolutioncanbepostprocessedfurther,thisiscoveredinthenextsection.68PostProcessingBoundaryConditionsSummaryandreviewSTAR-CCM+workflow:FromCADimporttosolutioninonepackage.Importgeometry.Defineboundaryconditions.Generatemesh.Definephysics.Setupanalysis.Runcase.Therestoftheexamplesinthiscoursegivemoredetailsonthevariousstagesoftheworkflow.69ImportGeometryPreparationBoundaryConditionsMeshingPhysicsSolverSettingsPostProcessingSummaryandreviewWheredoyouspecifythestandardmeshmodelsrequired?UnderGeometry>Operations.Wheredoyouspecifythephysicsmodelsrequired?UnderContinua–Physics.Howdoyouspecifyaboundaryasavelocityinlet?SelecttheboundaryandchangethetypeinthepropertieswindowWhydoyoucreatepostprocessingbeforerunningtheflowsolution?Soyoucanmonitorthesolutionwhileitisrunning.Whydoyouseparat