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简介：为空间地同类的Boltzmann方程的起始的价值问题被考虑。为这个问题的一个确定的数字计划被三个方法的使用开发未知功能以及碰撞积分的分解。在上这样，算法的几乎线性复杂性被完成。一些数字例子被举。[从作者抽象]

简介：AlatticeBoltzmannnumericalmodelingmethodwasdevelopedtopredictskinconcentrationaftertopicalapplicationofadrugontheskin.ThemethodisbasedonD2Q9latticespacesassociatedwiththeBhatnagar-Gross-Krook(BGK)collisiontermtosolvetheconvection-diffusionequation(CDE).Asimulationwascarriedoutindifferentrangesofthevalueofbound,whichisrelatedtoskincapillaryclearanceandthevolumeofdiffusionduringapercutaneousabsorptionprocess.Whenatypicaldrugisusedontheskin,thevalueofcorrespondstotheamountofdrugabsorbedbythebloodandtheabsorptionofthedrugaddedtotheskin.Theeffectofwasstudiedforwhentheregionofskincontactisalinesegmentontheskinsurface.

简介：格子Boltzmann方法在多相流动和化学反应中具有非常重要的意义,针对其在湍流、多孔介质流、燃烧、多孔介质燃烧中的应用进行了综述,分析了该方法在模拟这些复杂流体问题时存在的优点和缺点。分析结果表明,格子Boltzmann方法可以直观形象地对复杂流体问题进行模拟,是研究流体内部复杂变化过程的重要评价方法。

简介：AnewlatticeBoltzmannmodelforcompressibleperfectgasispro-posed.Thenumericalexampleshowsthatitcanbeusedtosimulateshockwaveandcontactdiscontinuity.Theresultsarecomparablewiththoseobtainedbytraditionalmethods.Theratioofspecificheatsγmaybechosenaccordingtotherequirementofproblems.

简介：WeconsiderdiffusivelimitoftheBoltzmannequationinaperiodicbox.WeestablishL~6estimateforthehydrodynamicpartPfofparticledistributionfunction,whichleadstouniformboundsglobalintime.

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简介：TheproblemofthemixedconvectioninacubiccavityisstudiedwithlatticeBoltzmannmethod.Amultiple-relaxation-timelatticeBoltzmannmodelforincompressibleflowinthecubiccavityandanotherthermallatticeBoltzmannmodelforsolvingenergy/temperatureequationareproposed.Thepresentmodelsarefirstvalidatedthroughacomparisonwithsomeavailableresults,andthen,wepresentadetailedparameterstudyonthemixedconvectioninthecubiccavity.ThenumericalresultsshowthattheHowandtemperaturepatternschangegreatlywithvariationsoftheReynoldsandRichardsonnumbers

简介：概述了国内外利用分子动力学研究流动的方法,主要介绍一种新的数值计算方法--格子Boltzmann方法.对此法的原理、模拟的模型及其在湍流流动中的应用进行了综述.分析这种方法在模拟湍流时存在的问题.为湍流流动研究者指出了一条新的途径--用分子动力学理论研究湍流流动.

简介：WederivedrevisedeffectivediffusionenergybarriersfollowingtheBoltzmanndistributionassumptionforimpurityatomsinabulkmaterialundertheimpactofvariouskindsofpointdefectstorevealtheinsightsofmigrationmechanisms.Theeffectivediffusionenergybarriersofcopperimpuritiesinbulkzirconiumwerecalculatedthroughthefirstprinciplemethodunderthepresentedhypothesis.Ourresults(?E||=1.27eV,?E⊥=1.31eV)agreedwellwiththeexperimentalresults(?E||=1.54eV,?E⊥=1.60eV),whichvalidatedbulkdiffusionasthemajormechanismforcopperdiffusioninzirconium.Theeffectivediffusionenergybarrierscouldbeusedforestimatingwhetherthedefectswillacceleratethediffusionorslowthemdownbyactingastrapsoftheimpurityatoms.Ontheotherhand,thefirstprincipleresultsoftheimpuritydiffusionviadefectscouldbefurtherusedasinputsoflargerscalecomputationalsimulations,suchasMC(MonteCarlo)orPhaseFieldcalculations.

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简介：Inthisstudy,amulti-relaxationtimelatticeBoltzmannmodelforshallowwaterinacurvilinearcoordinategridisdevelopedusingthegeneralizedformoftheinterpolationsupplementedlatticeBoltzmannmethod.TheTaylor-Coletteflowtestsshowthattheproposedmodelenjoysasecondorderaccuracyinspace.Theproposedmodelisappliedtothreetypesofmeanderingchannelswith180°,90°and60°consecutivebends.Thenumericalresultsdemonstratethatthesimulatedresultsagreewellwithpreviouscomputationalandexperimentaldata.Inaddition,themodelcanachievetheacceptableaccuracyintermsofthewaterdepthandthedepth-averagedvelocitiesforshallowwaterflowsincurvedandmeanderingchannelsoverawiderangeofbendangles.

简介：作者在一个三维的分层的领域考虑热转移问题的一种特定的类型，与边界上以及在接口上的非线性的Stefan-Boltzmann条件。决定边界的未知部分(或腐蚀)由Cauchy，可达到的部分上的数据是在工程的一个重要反的问题。这个问题的数学模型被介绍，前面的问题的well-posedness和反的问题的唯一被获得。关键词反的热问题-Stefan-Boltzmann条件-唯一2000苏布杰克特先生分类35R30-中国(号码07JC14001)的上海自然科学基金会支持的35K20工程，中国的教育部的博士程序基金会，为数学(号码10826105)的Tianyuan资金，国家基本研究程序(号码2005CB321701)和111工程(没有。B08018)。

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简介：文章介绍了格子Boltzmann方法的发展过程和原理,回望了格子Boltzmann方法在气泡模拟中的基本模型,并且对近来使用格子Boltzmann方法进行气泡运动模拟的相关文献进行了总结,指出最新的研究工作主要集中在对原有模型参数的细化和引入相关补充模型两个方面。

简介：AbstractIn[16]avisco-elasticrelaxationsystem,calledtherelaxedBurnettsystem,wasproposedbyJinandSlemrodasamomentapproximationtotheBoltzmannequation.TherelaxedBurnettsystemisweaklyparabolic,hasalinearlyhyperbolicconvectionpart,andisendowedwithageneralizedeotropyinequality.ItagreeswiththesolutionoftheBoltzmannequationuptotheBurnettorderviatheChapman-Enskogexpansion.Wedevelopaone-dimensionalnon-oscillatorynumericalschemebasedontherelaxedBurnettsystemfortheBoltzmannequation.Wecomparenumericalresultsforstationaryshocksbasedonthisrelaxationscheme,andthoseobtainedbytheDSMC(DirectSimulationMonteCarlo),bytheNavier-Stokesequationsandbytheextendedthermodynamicswiththirteenmoments(theGradequations).OurnumericalexperimentsshowthattherelaxedBurnettgivesmoreaccurateapproximationstotheshockprofilesoftheBoltzmannequationobtainedbytheDSMC,forarangeofMachnumbersforhypersonicflows,th

简介：LatticeBoltzmannmethodisoneofthewidelyusedinmultiphasefluidflow.However,thetwomaindisadvantagesofthismethodaretheinstabilityofnumericalcalculationsduetothelargedensityratiooftwophasesandimpossibilityofthetemperaturedistributiontobefedbackintothevelocitydistributionfunctionwhenthetemperatureissimulated.BasedonthecombinationprescribedbyInamuro,thelargedensityratiotwo-phaseflowmodelandthermalmodelmakesthedensityratioofthemodelsimulationtobeincreasedto2778:1byoptimizingtheinterfacedistributionfunctionoftwo-phasewhichimprovestheaccuracyofdifferentialformat.Thephasetransitiontermisaddedassourcetermintothedistributionfunctioncontrollingtwophaseorderparameterstodescribethetemperatureeffectonthegas-liquidphasetransition.Thelatentheatgeneratedfromthephasechangeisalsoaddedasasourcetermintothetemperaturedistributionfunctionwhichsimulatesthemovementoftheflowunderthecommoncouplingofdensity,velocity,pressureandtemperature.Thedensityandthetemperaturedistributionofsinglebubblearesimulated.Comparisonofthesimulationresultswithexperimentalresultsindicatesagoodagreementpointingouttheeffectivenessoftheimprovedmodel.

简介：ThispaperconstructsanewmultiplerelaxationtimelatticeBoltzmannmodelwhichisnotonlyfortheshockedcompressiblefluids,butalsofortheunshockedcompressiblefluids.Tomakethemodelworkforunshockedcompressiblefluids,akeystepistomodifythecollisionoperatorsofenergyfluxsothattheviscouscoefficientinmomentumequationisconsistentwiththatinenergyequationevenintheunshockedsystem.Theunnecessityofthemodificationforsystemsunderstrongshockisanalyzed.Themodel...

简介：Thewatertemperaturestratificationinlargereservoirsmighthaveseriousecologicalandenvironmentalconsequences.Themodelingofthetemperaturedistributionanditshistoryisofgreatimportancebothforstudyingtheunderlyingmechanismsandforcontrollingtheadverseeffects.Todevelopaneffectiveandefficientmethodforsimulationoftemporalandspatialtemperaturevariations,alatticeBoltzmannmethod(LBM)modelfor3-Dthermalbuoyancyflowsisproposedandvalidatedbythetemperaturedatameasuredinamodelreservoir.ThispaperdiscussesimportantaspectsoftheLBManditsturbulencemodel,analyzesthegravitysinkingmechanismofcoldcurrents,anddemonstratesthecomplexityofthetemperatureredistributionprocess.Goodagreementbetweenthesimulatedandmeasuredresultsshowsthatthenewlydevelopedmethodisfeasibleandpowerful,anditwillbeusedforthewatertemperaturepredictioninactualreservoirsinanearfuture.

简介：Acoupledimmersedboundary-latticeBoltzmannmethod(IB-LBM)isintroducedtosolvebiomimeticproblems.ComparedtotheconventionalIB-LBM,thestrictsatisfactionofno-slipboundaryconditionisimplementedinthecurrentmethod.Consequently,thephenomenonofflowpenetrationthatisfrequentlyobservedintheconventionalIB-LBMisfullyprevented,andsubsequentlytheforceontheboundarycanbecalculatedmoreaccurately.Thisfeatureisofimportanceforthesimulationofbiomimeticproblems.Moreover,byapplyingtherelationshipbetweenthevelocitycorrectionandforcingterm,theboundaryforcecanbecalculatedeasily.Severalbiomimeticproblemsarethensimulated.Basedonthegoodagreementbetweenthecurrentresultsandthoseintheliterature,itmaybeconcludedthatthepresentIB-LBMhasthecapabilitytohandlevariousbiomimeticproblems.