SPH(光滑粒子动力学)

InstituteofEngineeringThermophysics工程热物理研究所SmoothedParticleHydrodynamicsInstituteofEngineeringThermophysics工程热物理研究所ContentsApplicationsTheadvantagesofSPHBasicideasofSPHBackgroundInstituteofEngineeringThermophysics工程热物理研究所ContentsApplicationsTheadvantagesofSPHBasicideasofSPHBackgroundInstituteofEngineeringThermophysics工程热物理研究所BackgroundNumericalsimulationisaveryimportantapproach.Grid-basednumericalmethodssufferfromdifficultiesinsomeaspects.Themajordifficultiesareinheritedfromtheuseofgridormesh.InstituteofEngineeringThermophysics工程热物理研究所BackgroundMeshfreemethodMeshfreeparticlemethods(MPMs)SmoothedparticlehydrodynamicDPD,MD,SPHetc.MeshfreemethodcandealwiththeaboveproblemsSPHOneoftheoldestmeshfreeparticlemethodsInstituteofEngineeringThermophysics工程热物理研究所ContentsApplicationsTheadvantagesofSPHBasicideasofSPHBackgroundInstituteofEngineeringThermophysics工程热物理研究所BasicIdeasofSPH1.Insmoothparticlemethodthefluidisrepresentedasasetofparticlesthatcarrythepropertiesofthefluidandinteractaccordingtoequationofmotion.Theequationarederivedinaclearandconsistentwayfromthecontinuumequationandconsitutiverelationforthesystem.InstituteofEngineeringThermophysics工程热物理研究所BasicIdeasofSPH2.SPHisaintegralrepresentation.xdhxxWxfxf,xdxxxfxfxxxxxxxx0khxxwhenhxxWxxhxxWxdhxxWh0,,1,lim0InstituteofEngineeringThermophysics工程热物理研究所BasicIdeasofSPH3.Thekernelapproximationisthenfurtherapproximatedusingparticle.xdhxxWxfxf,ParticleapproximationTheparticleapproximationisperformedateverytimestepTheuseoftheparticledependsonthedistributionoftheparticlesInstituteofEngineeringThermophysics工程热物理研究所BasicIdeasofSPH4.Theparticleapproximationsareperformedtoalltermsrelatedtofieldfunctions.OrdinarydiffertialequationsParticledifferentialequationsTheODEsaresolvedateverytimestep,andtoabtainthetimehistoryofallvariablesforallparticles.5.becomegetInstituteofEngineeringThermophysics工程热物理研究所BasicIdeasofSPHThefluidispresentedbyparticlewhichfollowthefluidmotion.Eachparticlecarriesmass,velocityandotherqualiticle.SPHformulationisdirectlybasedontheresolutionofmacroscopicgoverningequationoffluidflow.6.SummaryInstituteofEngineeringThermophysics工程热物理研究所ContentsApplicationsTheadvantagesofSPHBasicideasofSPHBackgroundInstituteofEngineeringThermophysics工程热物理研究所TheAdvantagesofSPHSPHisaLagrangianmeshfreeparticlemethod.Theaccuracy,stabilityandadaptivelyareacceptable.Applicationareverywide.SPHissuitabletofollowlargesurfacedeformationinvolvingfreesurfaceandinterfacial.DiscretesystemContinuumsystemsMicro-scaleMacro-scaleInstituteofEngineeringThermophysics工程热物理研究所ContentsApplicationsTheadvantagesofSPHBasicideasofSPHBackgroundInstituteofEngineeringThermophysics工程热物理研究所ApplicationsCaseone----dropletimpactingliquidsurface1.surfacetension----itsmacroscopicdescriptionYoung-Laplaceequation2.Threetypesparticles----realparticlesside-wallvirtualparticlesimagevirtualparticle3.Twotypesofboundaries----surfaceboundaryrigidboundaryConclusion:SPHmethodhasacertainsuperiorityinsimulatingthestrongnon-lineartransientfreesurfaceflow.NumericalsimulationofdropletimpactingliquidsurfacebySPH.(2011)LIDaMing.SchoolofCivilEngineering,TianjinUniversityInstituteofEngineeringThermophysics工程热物理研究所ApplicationsCasetwo----coalescenceofcollidingdrops1.Thebackgroundofbinarycoalescence.2.Thedimensionsionlessnumbers.3.Thetypesofoutcome.4.Theprocessofcolliding.CoalescenceofcollidingvanderWaalsliquiddrops.(2005)attractiveforcecohesivepressureVDWequationsurfacetensionIabtaininformationsUniversite´deMontpellierIIInstituteofEngineeringThermophysics工程热物理研究所ApplicationsModelingofsurfacetensionandcontactangleswithsmoothedparticlehydrodynamics(2005)Casethree----Flowthroughfracturejunctionssurfacetensioncontactanglespairwisefluid-fluidandfluid-solidparticle-particleinteractionsNumericalexperimentTheresultswereinqualitativeagreement.InstituteofEngineeringThermophysics工程热物理研究所