gridgen官方教材

1Inthissession:GridgenTerminology.GUIComponents.GridgenHelp.Building2DStructuredGrids.Building2DUnstructuredGrids.Tutorial:“2DBump:BasicSkills.”GridgenTrainingOverview2What’sanEntity?Anentityisanyindividualelementthatmakesuppartofagridorgeometry.GridgenTerminologyDomainsBlocksConnectorsExamplesofGridgenentities3ConnectorsGridgenTerminologyConnectorsarethecurveentitiesthatdefineallgridedges.Connectorscontainoneormoresegments.Nodesmarkconnectorendpoints.ControlPointsletuserdefinesegmentshape.Connectorsaredimensionedbynumberofgridpointswithadistributiondescribinghowtheyareplaced.4DomainsGridgenTerminologyADomainisasurfacegridentityboundedbyedges.StructuredDomainsconsistsolelyofquadrilateralelements.UnstructuredDomainsconsistsolelyoftriangularelements.StructuredDomainshaveexactlyfouredges.UnstructuredDomainsgenerallyhaveoneedge(moreiftheytheencompassholes).Eachedgecontainsoneormoreconnector(s).5BlocksGridgenTerminologyABlockisavolumegridentityboundedbyfaces.StructuredBlocksconsistsolelyofhexahedralelements.UnstructuredBlockscanconsistoftetrahedral,pyramidal,and/orprismaticelements.StructuredBlocksareboundedbyexactlysixfaces.UnstructuredBlocksgenerallyhaveoneface(moreiftheyencompassholes).Eachfacecontainsoneormoredomain(s).6GridsAGridiscomposedofvolumeand/orsurfacegridblocks.StructuredGridscontainonlyquadrilateralandhexahedralelements.UnstructuredGridscontainonlytriangularandtetrahedralelements.HybridGrids(suchasthatshownhere)containbothstructuredandunstructuredgridelements(quads,triangles,hexes,andtets)andcanalsohaveprismaticandpyramidalelements.GridgenTerminology7DatabasesInGridgen,databasesrefertocollectionsofgeometryinformationthatcanbeusedtodefinetheshapetowhichthegridistobebuiltandtypicallycomefromcomputeraideddesign(CAD)software:Analytic–curveandsurfaceinformationfromaCADfile.Shell–discreteunstructureddatabasesurfaceentity,generallyimportedfromstereolithography(STL)formattedfiles.Network–bilinear(non-slopecontinuous)databasesurfaceentity,generallyimportedfromPlot3Dformattedfiles.Ofcourse,databasesarenotnecessarytobuildgridswithGridgen,butareoftenneededforimportingcomplexgeometries.GridgenTerminology8TheGridgenScreenGUIComponentsVersionListsGridgenversionnumberStatusTalliesnumberofgridentitiesMessageProvidesinstructionsandpromptsfortextinputTextInputEchoesdataenteredviakeyboardBlackboardDisplayscontext-sensitivegraphicalandtabulardata(akaDiagnosticorBrowserwindow)CommandMenuListsGridgenCommands(akaButtonMenu)DisplayShowsgraphicalimageofgridanddatabase9TheMouse:Pan,Zoom,andPickLeftMouseButton:PanPressandholdtheleftmousebuttontopanthemodelimageinthedisplaywindow.Whilepanning,themousecursorchangesto:CenterMouseButton:ZoomPressandholdthecentermousebuttontochangethemodelimage’ssize,pushingthemouseawayfromyouzoomsoutwhilepullingittowardsyouzoomsin.Formicewithacenterwheel,thewheelcanberolledorhelddowntocontrolzoom.Ontwobuttonmice,zoomingisaccomplishedbyholdingbothbuttonsdown.Whilezooming,themousecursorchangesto:RightMouseButton:PickPressandreleasetherightmousebuttontoselectcommandsfromthecommandmenuorpickentitiesinthedisplaywindoworbrowserlist.Whilepicking,themousecursorchangesto:GUIComponents10SomeMouseOptionsGUIComponentsThefunctionsoftheleftandrightmousebuttonscanbereversed,sothatleftisforpickingandrightisforpanning.ThiscanbedonebyselectingLeftPk.Whendealingwithsmallergeometricentities,itmayalsobedesirabletoreducethemousesensitivityinpanning,zooming,androtatingthescreenimage.Thiscanbedonebyclickingonthebutton(moreclicks,lesssensitivity).Youmaywishtochangesomeofthedefaultmousesettings.ThesecanbeaccessedbyselectingtheDisplayorDispsubmenufromGridgen’sMAINMENU.11ModelRotationsYXZScreenCoordinatesBodyCoordinatesGUIComponentsGridgenhastwodistinctcoordinatesystems:screencoordinatesandbodycoordinates.Inadditiontopanning,zooming,andpicking,themousebuttonscanalsobeusedtorotatethemodelscreenimage.ThisisdonebycombiningtheleftandcentermousebuttonswiththeCtrlkey:Ctrl+leftmousebutton:screenxandyrotations.Ctrl+centermousebutton:screenzrotations.12ModelRotations(Continued)Formorepreciserotationcontrol,thefollowingnumpadkeyscanbeused:7rotatesaboutthexscreenaxis.8rotatesabouttheyscreenaxis.9rotatesaboutthezscreenaxis.NumLockrotatesaboutthexbodyaxis./rotatesabouttheybodyaxis.*rotatesaboutthezbodyaxis.Additionalrotationfeaturescanbeaccessedwiththefollowing“hotkeys”:PageDownusedwithanyofthex-y-zbody/screenkeysresultsina90deg.rotationaboutthecorrespondingcoordinatedirection.PageUpusedwithanymodelmanipulation,whetherbymouseorkeyboard,provides3xaccelerationoftheoperation.+and–numpadkeysreversethedirectionofakeyboardmodelrotation.Altusedwithanumpadmodelrotationgivesasingleincrement(3deg.)rotation.GUIComponents13CommonlyUsedHotKeysGUIComponentsNote:HotkeysforGridgencommandsareshownaspinkcharactersonthecorrespondingGUIbuttons.14FileBrowsingSelectingInput/OutputfromtheMAINMENUopenstheINPUT/OUTPUTCOMMANDSsubmenufromwhich(inthisexample)theINPUTGridgenFILEsubmenuhasbeenselected.TheBrowserWindowshowstheappropriate