如果我们选择了最能为人类的福利而劳动的职业

FronTierandApplicationstoConvectionDominatedProblemsXiaolinLi,WurigenBo,JamesGlimmAndtheFronTierteamDepartmentofAppliedMathandStatisticsSUNYatStonyBrook2Outlineofthetalk1.BenchmarkexamplesofFronTier2.ConvectionDominatedProblems3.Otherproblems4.CouplingFronTierwithotherpackages5.ChallengestoFronTier3AquotationfromAlbertEinstein1.StonyBrook,AMSDepartment,galaxycluster(over500processors)2.StonyBrook,CEAS,Seawulfcluster3.NewYorkBlue:103.22teraflopsMajorComputingResources:4如果我们选择了最能为人类的福利而劳动的职业，我们就不会为它的重负所压倒，因为这是为全人类所做的牺牲，那时我们所感到将不是一点点自私而可怜的欢乐，我们的快乐属于千万人，我们的工作并不显赫一时，但将永远存在，而面对我们的骨灰，高尚的人们将会洒下热泪卡尔.马克思5TheDiscreteMeshRepresentationinFrontTrackingVolumefillingrectangularmesh(EulerianCoord.)(N-1)dimensionalLagrangianmesh(interface)A3DInterfaceA2DRepresentationYX(i,j)6FronTierAsoftwarepackagebasedonthefronttrackingmethod7FrontTracking:Scientificapplicationstointerfacialphysics,themethodologyandsoftware1.2006-2009,over36,000newlinesofcode,removalofhundredsofrun-timebugs,setupbenchmarks.2.CollaborationswithANL,BNL,LLNL,ORNL,PNNL,Oxford.3.Over20publicationsandmanyconferencepresentations.4.ImplementediMeshinterface,supportSciDACapplications.5.InteroperabilitywithHypreandPETSc,couplingwithparabolicandellipticsolvers,implicitandCrank-Nicolsonandincompressiblesolver.FronttrackingwasfirstintroducedByRichtmyerin1950’s.ItwasUsedbyMorettiforcomputationInaerodynamicsproblems.Extensionto2Dand3DstartedByJ.GlimmandO.McBryanIn1980’satCourantInstitute.8InterfaceTopologicalChanges„Algorithmstohandletopologicalchanges„Gridfreetracking(GF)„Gridbasedtracking(GB)„Locallygridbasedtracking(LGB)TangledinterfaceGFLGBGB9RobustLocallyGridBased(LGB)UntangleƒAdvantageƒLocal,itissuitableforlargescalecomputing.ƒRobust,Itgeneratestopologicallyvalidsurfacemesh.„Arobustalgorithmtoreconnectagridbasedsurfacemeshwithagridfreesurfacemesh10InterfaceTopologicalChanges„Gridbasedtrackingisrobustbuttoodiffusive.„Challenge:Robustnessofthealgorithmiscrucialforlargescalecomputing.GridbasedtrackingGridfreetracking11Zalesak’sslotteddisk(2D)12InterfaceTopologicalChanges„Gridbasedtrackingisrobustbuttoodiffusive.„Challenge:Robustnessofthealgorithmiscrucialforlargescalecomputing.GridbasedtrackingGridfreetracking13ResolutionTestFronTiercanprovideResolutionofsurfaceDownto1/200ofmeshspacing14模拟维模拟模拟晶体结晶过程Resolutionindependentofmesh15Fronttrackingreversaltestofinterfaceinthedeformationvelocityfield162DReversalTest17Fronttrackingreversaltestofinterfacein3Ddeformationvelocityfield646464××128128128××0.0=t0.3=t5.1=t18VOFbyKothe(2005)0.3=t5.1=t5.1=t0.3=t19模拟维模拟模拟晶体结晶过程Deformationof3Dsurfacemesh202DTopologicalBifurcationFronTierisequippedWithrobustandEfficientbifurcationFunctionsformeshesRepresentingthePropagatingfront21模拟维模拟模拟晶体结晶过程Topologicalmergingof3Dsurfacemesh22Examples„Interfacebifurcationandmergingarecommonlyobservedinmultiphaseflowmeshbifurcationinacurvaturedependentsurfacepropagationmeshmerginginadropletcollisionsimulation23εκ−=0vvn模拟维模拟模拟晶体结晶过程Geometrydependentinterfacevelocity24ConvectiondominatedPDE•Hyperbolicequation•Hyperbolic-elliptic(NSequation)•Parabolicequation•Hyperbolic-parabolic(convection-diffusion)25FronTierApplicationstothestudyofRayleigh-TaylorInstability(CouplingwithhyperbolicEuler’sequationforgasdynamics)26IncompressibleRayleigh-Taylorinstability2728FronTierapplication:chaoticmixing29FronTierapplication:chaoticmixingChaoticmixingisnotonlyimportanttoICF,butalsoatestoflargescaleFronTierapplicationtopetascalecomputing.Wehaveimplementedaloadbalancedparallelalgorithmandranupto1024processorsonNewYorkBlue.CollaborationwithB.Cheng,JohnGrove,andD.SharpatLANL.303DTurbulentMixing31FronTierApplicationstothestudyofRichtmyer-MeshkovInstability32InertialConfinementFusion(ICF)33SimulationofSphericalRM34FronTierApplicationstoBiodieselJetSimulation3Dsimulationforprimaryjetbreakup36模拟三维内燃机喷嘴Asknotwhattheearthcandoforus,askwhatwecandofortheearthAmericanconsumesabout200billiongallonsperyear,a10%savingwillbe20billiongallonamountstomorethan40billiondollars,nottomentionthebenefittotheenvironment.37Burningbiofuelinanengine1.Understandingthedifferencebetweenconventionalfuelandbiofuel:a)Ethanolusedtoblendwithgasolineforautomobile;b)Biodieselblendwithdistillatepetroleumfuelssuchasdiesel,keroseneandheatingoilsforuseindieselengines,boilerspossiblyturbines.2.Howtoburncleanlyanduniformly:Theprerequisiteforanoptimizedcombustionisanoptimizedfuelinjectionspray.3.Whatwillaffecttheformationofspray:Thephysicalpropertiesofthefuel,thegeometryoforificeandtheapplicationofpressure,thedynamicsofthefluidsthroughthenozzle.38Surfacemeshevolutioninjetsimulation39Verification:Kelvin-HelmholtzInstability0.03130.02050.009480160320FT/GFMMeshpermodeTherelativeerrorsofthegrowthrateComparisonwiththedispersionrelationdispersionrelation40Verification:RayleighInstability0.28530.17020.06720.13960.06070.032151020FT/GFM(3D)FT/GFM(2D)NumberofcellsonradiusTherelativeerrorsofthegrowthrateComparisonwiththedispersionrelationdispersionrelation41ParallelPerformanceofFT157.1159.81638416×16×64256×256×1024157.1158.2819216