简介：-Inthispaperasimpleandefficientimplicitfinite-differenceschemeisusedfordepth-averagedtwo-dimensionalstormsurgemodel.Thisfinite-differenceschemeissimplerandmoreefficientthanthewi-dely-usedADIscheme.Accuracyanalysisandstabilityanalysisindicatethattheschemehastwo-orderac-curacyandisunconditionallystablewhenthegridsizeisconstant.ThepresentanalysisresultsshowthattheschemeisofhighernumericalaccuracythanthatintroducedbyMaa(1990).Aftertestedbyidealmod-els,acalculationexampleofarealtyphoonsurgeiscarriedout,theresultsofthenumericalsimulationco-incidewellwiththeobserveddataandtheaccuracyissufficientforengineeringapplications.

简介：Theunbondedflexiblepipeofeightlayers,inwhichallthelayersexceptthecarcasslayerareassumedtohaveisotropicproperties,hasbeenanalyzed.Specifically,thecarcasslayershowstheorthotropiccharacteristics.Theeffectiveelasticmoduliofthecarcasslayerhavebeendevelopedintermsoftheinfluenceofdeformationtostiffness.Withconsiderationoftheeffectiveelasticmoduli,thestructurecanbeproperlyanalyzed.Alsotherelativemovementsoftendonsandrelativedisplacementsofwiresinhelicalarmourlayerhavebeeninvestigated.Athree-dimensionalnonlinearfiniteelementmodelhasbeenpresentedtopredicttheresponseofflexiblepipesunderaxialforceandtorque.Further,thefrictionandcontactofinterlayerhavebeenconsidered.Comparisonbetweenthefiniteelementmodelandexperimentalresultsobtainedinliteraturehasbeengivenanddiscussed,whichmightprovidepracticalandtechnicalsupportfortheapplicationofunbondedflexiblepipes.

简介：-Byusinggas-liquidtwo-phaseflowtheory,amodifiedmathematicalmodelbasedonthecomputationalfluiddynamicsmethodSIMPLE(Semi-ImplicitMethodforPressure-LinkedEquations)isintroducedtoinvestigateimplosionphenomenainhighpressurechamberssystematically.Atheoreticalsimulation-predictionmethod,whichisindependentofexperimentaldata,isdevelopedinthepaperandgreatimprovementhasbeenmadeonthetopic.Inthepaper,variousimplosionsituationshavebeensimulatedandpredicted.Effectsofaseriesoffactorsinfluencingimplosionresultsandmethodsofreducingimplosiondangerhavebeenanalysed.Theanalysisresultsareofimportancetounderwaterengineeringpractice.

简介：Hydrodynamiccharactersonahorizontal,thin,rigidplatelocatedbeneaththefreesurfacearenumericallyinvestigated.Assumingalinear,time-harmonicpotentialflowandutilizingGreenidentity,thegoverningLaplaceequationcanbesimplifiedintoFredholmintegralequationofthesecondkind.Supposinglinear-orderdiscontinuouselementsalongintersectingverticalboundaries,andbyuseoftheboundaryelementmethod,numericalsolutionaboutsourcestrengthdistributionontheplatecanbechangedintoaseriesofalgebraicequations.The3DGreenfunctionisintroducedtosetuptheintegralequations,andtheGMRESsolverisperformedforsolvingthelargedenselinearsystemofequations.Theadded-mass,dampingforceandexcitingforceareevaluateddirectlyfromtheequations.Itisfoundthattheadded-masscoefficientbecomesnegativeforarangeoffrequencieswhentheplateissufficientlyclosetothefreesurface.

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简介：Athree-stepfiniteelementmethod(FEM)togetherwithLargeEddySimulation(LES)isap-pliedtoincompressibleturbulentflowaroundseabedpipelinesatrelativelyhighReynoldsnumbers.Bothtwo-dimensionalandthree-dimensionalnumericalsimulationiscarriedouttodeterminethethree-dimensionaleffect.Theresultsofnumericalsimulationagreequitewellwiththewaveforcesactingonpipelinemodelsmeasuredinphysicalmodeltest.

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简介：Afive-layerprimitiveequationmodelwasusedinthestudyofrapidcyclogenesisoversea.Thenumericalsimulationsshowthat’theTibetanPlateau,large-scalebaroclinicityandheatfluxfromtheseasurfacearethethreeimportantagentstoproducecyclonicvorticityalongtheeastcoastofChina.Thediagnosticcomputationofa24hcontrolsimulationindicatesthatthenonlinearvorticityadvec-tion,baroclinicityanddiabaticheatingarealsoresponsibleforthedevelopmentoftheextratropicalcyclonesoverseas.

简介：-Driftcurrentinducedbywindandwavesisinvestigatedwithphase-averagedNavier-StokesequationinwhichtheReynoldsstressisclosedbyk-εmodel.Thegoverningequationsaresolvedbythefinitevolumemethodinasystemofnonorthogonalcoordinateswhichisfittedtothephase-averagedwavesurface.Thepredicteddriftcurrentisfairlyreasonableandthedragcoefficientofsea-surfacepredictedwiththenewlydevelopedinterfaceconditionsshowsgoodagreementwithpreviousmeasurementswhenbreakingwavesdonotexist.

简介：Inthispaper,thedynamicresponseofundersea-+towedsystemsisnumericallysimulated.Atwobodytowedsystemisespeciallyconsideredindetail.Thefactorsinfluencingtheheaveoftowed-bodies,suchastheweightofthetowed-body(inseawater),thelengthandtheweight(inseawater)perunitlengthofthecablebetweentowed-bodiesandtowingship,areinvestigatedindetail.Calculationsshowthatthetwo-bodytowedsystemcangreatlyincreasesthestabilityofthetowedsystem.

简介：Inthispaper,anumericalmodelof2Dweaklycompressiblesmoothedparticlehydrodynamics(WCSPH)isdevelopedtosimulatetheinteractionbetweenwavesandthinstructures.Anewcolordomainparticle(CDP)techniqueisproposedtoovercomedifficultiesofapplyingtheghostparticlemethodtothinstructuresindealingwithsolidboundaries.Thenewtechniquecandealwithzero-thicknessstructures.Toapplythisenforcingtechnique,thecomputationalfluiddomainisdividedintosubdomains,i.e.,boundarydomainsandinternaldomains.Acolorvalueisassignedtoeachparticle,andcontainstheinformationofthedomainsinwhichtheparticlebelongstoandtheparticlescaninteractwith.Aparticle,nearbyathinboundary,ispreventedfrominteractingwithparticles,whichshouldnotinteractwithontheothersideofthestructure.Itispossibletomodelthinstructures,orthestructureswiththethicknessnegligiblewiththistechnique.TheproposedWCSPHmoduleisvalidatedforastillwatertank,dividedbyathinplateatthemiddlesection,withdifferentwaterlevelsinthesubdomains,andisappliedtosimulatetheinteractionbetweenregularwavesandaperforatedverticalplate.Finally,thecomputationiscarriedoutforwavesandsubmergedtwin-horizontalplateinteraction.Itisshownthatthenumericalresultsagreewellwithexperimentaldataintermsofthepressuredistribution,pressuretimeseriesandwavetransmission.

简介：Thispaperaimsatinvestigationofthedynamicpropertiesofgravitycageexposedtowavesbyuseofanumericalmodel.Thenumericalmodelisdeveloped,basedonlumpedmassmethodtosetuptheequationsofmotionofthewholecage;meanwhilethesolutionsofequationsaresolvedbytheRunge-Kutta-Vernerfifth-orderandsixth-ordermethod.Physicalmodeltestshavebeencarriedouttoexaminethevalidityofthenumericalmodel.Theresultsbythenumericalsimulationagreewellwiththeexperimentaldata.

简介：Forthesimulationofthenonlinearwavepropagationincoastalareaswithcomplexboundaries,anumericalmodelisdevelopedincurvilinearcoordinates.Inthemodel,theBoussinesq-typeequationsincludingthedissipationtermsareemployedasthegoverningequations.Inthepresentmodel,thedependentvariablesofthetransformedequationsarethefreesurfaceelevationandtheutilityvelocityvariables,insteadoftheusualprimitivevelocityvariables.TheintroductionofutilityvelocityvariableswhicharetheproductsofthecontravariantcomponentsofthevelocityvectorandtheJacobimatrixcanmakethetransformedequationsrelativelyconcise,thetreatmentoflateralboundaryconditionseasierandthedevelopmentoftheprogramsimpler.Thepredictor-correctormethodandfive-pointfinite-differenceschemeareemployedtodiscretizethetimederivativesandthespatialones,respectively.Thenumericalmodelistestedforthreecases.Itisfoundthatthenumericalresultsareingoodagreementwiththeanalyticalresultsandexperimentaldata.

简介：一个二维的数字模型被建议在江苏省从一个发电厂模仿热分泌物。在模型的方程在于oftwo维的非稳定的浅水区方程和热废物搬运方程。Finitevolume方法(FVM)习惯于discretize切开的浅水区方程，和流动差别(FDS)计划被使用。有一样的温度增长的计算区域在海水上显示出热分泌物的效果。在模仿的结果和试验性的数据hows之间的比较好同意。它显示这个方法能在沿海的区域在热传递模拟给高精确。

简介：Toinvestigatethemechanismofsecondarycirculationsinripcurrentsystems,andtoexploretherelationshipbetweenwaveconditionsandsecondarycirculationintensity,aseriesofnumericalexperimentsisperformedusingcouplednearshorewavemodelandcirculationmodel.Intheseexperiments,theripcurrentsandsecondarycirculationsgeneratedabovebarredbeacheswithripchannelsaresimulated.Acomparisonexperimentisconductedtoinvestigatetheformationandhydrodynamicsofthesecondarycirculations.Modelresultsindicatethatthesecondarycirculationsconsistofalongshoreflowsdrivenbywaveset-upneartheshoreline,partofthefeedercurrentsdrivenbythewaveset-upoverthebars,andonshoreflowsattheendoftheripchanneldrivenbywavebreakingandconvection.Theexistenceofthesecondarycirculationbarelyaffectstheripcurrent,butnarrowsandintensifiesthefeedercurrents.Threegroupsofexperimentsofvaryingincidentwaveconditionsareperformedtoinvestigatetherelationshipbetweenwaveconditionsandsecondarycirculationintensity.Thevelocityofthealongshoreflowofthesecondarycirculationissensitivetothevariationoftheincidentwaveheightandwaterdepth.Itisalsofoundthatthealongshoreflowintensityisindirectproportiontothealongshorevariationofthewaveheightgradientbetweenthebarsandtheshoreline.

简介：Quartercircularbreakwater(QCB)isanew-typebreakwaterdevelopedfromsemi-circularbreakwater(SCB).ThesuperstructureofQCBiscomposedofaquartercircularfrontwall,ahorizontalbaseslabandaverticalrearwall.ThewidthofQCB'sbaseslabisabouthalfthatofSCB,whichmakesQCBsuitabletobeusedonrelativelyfirmsoilfoundation.ThenumericalwaveflumebasedontheReynoldsaveragedNavier-StokesequationsforimpressibleviscosityfluidisadoptedinthispapertosimulatethehydraulicperformancesofQCB.SincethegeometryofbothbreakwatersissimilarandSCBhasbeenstudiedindepth,thehydraulicperformancesofQCBaregivenincomparisonwiththoseofSCB.

简介：Tostudythecompactionlawandoverpressureevolutionindeepwatershallowsediments,alarge-straincompactionmodelthatconsidersmaterialnonlinearityandmovingboundaryisformulated.Themodelconsidersthedependenceofpermeabilityandmaterialpropertiesonvoidratio.ThemodifiedCam-Claymodelisselectedastheconstitutiverelationsofthesediments,andthedeactivation/reactivationmethodisusedtocapturethemovingtopsurfaceduringthedepositionprocess.Aone-dimensionalmodelisusedtostudythecompactionlawoftheshallowsediments.Resultsshowthatthesettlementoftheshallowsedimentsislargeundertheirownweightduringcompaction.Thevoidratiodecreasesstrictlywithburialdepthanddecreasesmorequicklyneartheseafloorthaninthedeeperlayers.Thegenerationofabnormalpressureintheshallowflowsandsiscloselyrelatedtothecompactionlawofshallowsediments.Thetwomainfactorsthataffectthegenerationofoverpressureinthesandsaredepositionrateandpermeabilityofoverlyingclaysediments.Overpressureincreaseswithanincreaseindepositionrateandadecreaseinthepermeabilityoftheoverlyingclaysediment.Moreover,anupperlimitfortheoverpressureexists.Atwo-dimensionalmodelisusedtostudythedifferentialcompactionoftheshallowsediments.Theporepressurewillstillincreaseduetotheinflowoftheporefluidfromtheneighboringclaysedimenteventhoughthedepositionprocessisinterrupted.

简介：-Basedonfieldwavedata,anempiricalformulaofwaveenvelopespectrumisgiveninthispaper.Thenthemethodsofbothnumericalandphysicalsimulationofseawavegroupswiththegivenspectrumandgroupinessparametersaresuggested.

简介：Multi-directionalirregularwavesaresimulatedonthebasisofthegivendirectionalspectrumusingadoublesummationmodel,asingledirectionperfrequencymodelandasinglesummationmodel.Theirresultsarecompared.Itisshownthatthesingledirectionperfrequencymodelproposedinthispapercangeneratearealisticwavefield.Theeffectsofthemodelparametersonthesimulatedresultsarealsostudiedinthispaperandcorrespondingsuggestionsaregiven.

简介：Theeffectsofvarioustypesofwavesonverticalplaneturbulentjetsarestudiednumericallyinthepaper.Athree-dimensionalnumericalmodelinσ-coordinateisdevelopedtostudytheseproblemsbyuseoflargeeddysimulationmethod.Turbulenceismodeledbyadynamiccoherenteddymodel.Numericalresultsincludingthedistributionofvelocity,thedecaylawofthemeanvelocityalongaxis,theturbulentReynoldsstressesandthevolumefluxperunitwidthwithoutwave,inthefirst-orderStokeswaves,inthesecond-orderStokeswaves,inthefifth-orderStokeswaves,inthesolitarywavesandinrandomwavesarecomparedandanalyzed.Afocusoncoherentstructures,probabilitydensityfunctionsandcorrelationfunctionsofjetsisalsoinvestigated.Thenumericalresultsareofgreattheoreticalimportanceforunderstandingjetturbulentbehaviorsindifferenttypesofwaves.