简介：Smoothedparticlehydrodynamics(SPH)isaLagrangianmeshlessparticlemethod.Itisoneofthebestmethodforsimulatingviolentfreesurfaceflowsinfluidsandsolvinglargefluiddeformations.Dambreakingisatypicalexampleoftheseproblems.ThebasisofSPHwasreviewed,includingsometechniquesforgoverningequationresolution,suchasthesteppingmethodandtheboundaryhandlingmethod.Thennumericalresultsofadambreakingsimulationwerediscussed,andthebenefitsofconceptslikeartificialviscosityandpositioncorrectionwereanalyzedindetail.Whencomparedwithdambreakingsimulatedbythevolumeoffluid(VOF)method,thewaveprofilegeneratedbySPHhadgoodagreement,butthepressurehadonlyreasonableagreement.Improvingpressureresultsisclearlyanimportantnextstepforresearch.

简介：Thescatteringprobleminvolvingwaterwavesbysmallundulationontheporousocean-bedinatwo-layerfluid,isinvestigatedwithintheframeworkofthetwo-dimensionallinearwaterwavetheorywheretheupperlayeriscoveredbyathinuniformsheetoficemodeledasathinelasticplate.Insuchatwo-layerfluidthereexistwaveswithtwodifferentmodes,onewithalowerwavenumberpropagatealongtheice-coverwhilstthosewithahigherwavenumberpropagatealongtheinterface.Anincidentwaveofaparticularwavenumbergetsreflectedandtransmittedoverthebottomundulationintowavesofbothmodes.PerturbationanalysisinconjunctionwiththeFouriertransformtechniqueisusedtoderivethefirst-ordercorrectionsofreflectionandtransmissioncoefficientsforboththemodesduetoincidentwavesoftwodifferentmodes.Onespecialtypeofbottomtopographyisconsideredasanexampletoevaluatetherelatedcoefficientsindetail.Thesecoefficientsaredepictedingraphicalformstodemonstratethetransformationofwaveenergybetweenthetwomodesandalsotoillustratetheeffectsoftheicesheetandtheporosityoftheundulatingbed.