简介：Fingeringphenomenaarecommonoccurrenceinthenaturalworld.Itgenerallytakesplacewhenalessviscousfluiddisplacesamoreviscousfluidtypicallyinporousmedia.Nowadays,suchphenomenahaveextensivelybeenstudiedduetoitsimportanceinmanyindustrialfields.Inthispaper,theeffectsofsurfacewettabilityonfingerpatternarestudiedandsimulatednumericallybytheLatticeBoltzmannmethod(LBM).Thedisplacementefficiencyisinvestigatedbyusingtwoparameters,namely,thebreakthroughtimeandthearealsweepefficiency.Thesimulationhasdemonstratedthatsurfacewettabilitywillinfluencethefingerpatternnomatterthegravityisconsideredornot,butinthepresenceofgravity,thefingerpatternismuchmorecomplicatedandirregularduetothecoexistenceandcompetitionofcapillaryforce,viscousforceandgravity.

简介：Unsteadymotionofaverticallyfallingnon-sphericalparticlehasattractedconsiderableattentionduetoitsfrequentapplicationsinnatureandindustry.Aseriesofsemi-analyticalmethodshavebeenusedtoraisetheresults’accuracyaswellaswideningtheregionofconvergence.Thecurrentstudypursuedanewanalyticalsolutionfortheunsteadymotionofarigidnon-sphericalparticleinaquiescentNewtonianfluid,basedontheOptimalHomotopyAnalysisMethod.Withaviewtowardsobtainingthehighestlevelofaccuracyandensuringtheconvergenceoftheanalyticalresults,theaveragedresidualerrorswereobtainedandminimized.Inadditiontoflexibility,itwasalsoproventhattheproposedmethodcanleadtocompletelyreliableandpreciselyaccurateresults.Basedontheseriessolution,theeffectsofphysicalparametersontheterminalsettlingvelocity(i.e.thegreatestvelocitythatafallingbodymayreach)andtheaccelerationtime(i.e.thetimethataparticlereachesthesettlingvelocity)areinvestigated.

简介：Thevibrationalfrequencyanalysisoffiniteelastictubefilledwithcompressibleviscousfluidhasreceivedplentyofattentioninrecentyears.Toapplyfrequencyanalysistodefectdetectionforexample,itisnecessarytoinvestigatethevibrationalbehaviorunderappropriateboundaryconditions.Inthispaper,wepresentadetailedtheoreticalstudyofthethreedimensionalmodalanalysisofcompressiblefluidwithinanelasticcylinder.Thedispersionequationsofflexural,torsionalandlongitudinalmodesarederivedbyelastodynamictheoryandtheunsteadyStokesequation.ThesymbolicsoftwareMathematicaisusedinordertofindthecoupledvibrationfrequencies.Thedispersionequationisdeducedandanalyticallysolved.Thefiniteelementresultsarecomparedwiththepresentmethodforvalidationandanacceptablematchbetweenthemareobtained.

简介：Inthisarticle,weareconcernedwiththeglobalweaksolutionstothe1Dcompressibleviscoushydrodynamicequationswithdispersioncorrectionδ~2ρ((φ(ρ))xxφ′(ρ))xwithφ(ρ)=ρα.ThemodelconsistsofviscousstabilizationsbecauseofquantumFokker-PlanckoperatorintheWignerequationandissupplementedwithperiodicboundaryandinitialconditions.Thediffusiontermεuxxinthemomentumequationmaybeinterpretedasaclassicalconservativefrictiontermbecauseofparticleinteractions.Weextendtheexistenceresultin[1](α=1/2)to0<α≤1.Inaddition,weperformthelimitε→0withrespectto0<α≤1/2.

简介：我们调查在压电的分层的结构的起始的应力的效果装载了与的经分解粘滞爱的散、稀释的特征上的液体飘动，它包含薄压电的层完美地结合了到无界的有弹性的底层。在压电的层的起始的应力的效果并且粘滞爱波浪的阶段速度上的液体的系数被分析。数字结果被介绍并且讨论。分析方法和结果能为化学药品和biosensing液体传感器的设计是有用的。

简介：Ashocktubeisusedtoinvestigatethebubbledynamicsundersuddendecreaseofambientpressure.Boththeoscillatingandmonotonouslygrowingbubblesweresimultaneouslyobserved.TheoreticalapproachisbasedontheRayleigh-PlessetandHerring'sequationsforincompressibleandcompressibleliquids,respectively.Consideringthelinearapproximationoftheseequationsforthequasiequilibriumstate,twocriticalWebernumbersaredefined.Theyenableonetopredictthefollowingmodesofthebubbleexpansion:(i)unboundedgrowth,(ii)asymptoticgrowthtolimitedvolumeand(iii)attenuatedoscillations,dependingonthepressureforce,viscosityandcompressibilityoftheliquid.

简介：Theviscouspump,whichhasarotorwithahelicalsquarechannel,isstudiedexperimentally.Thenon-dimen-sionalchannelcurvatureistakentobeabout0.1.Threetypesoftorsionofthechannelaremadetoinvestigatethetorsioneffectontheflowcharacteristics.Wemeasurethefluxthroughthechannelataconstantrotorspeedbychangingthepressuresattheentranceandexitofthepump.Wealsoobservethesecondaryflowatacross-sectionofthechannel.Someoftheresultsobtainedareshownasfollows:Thefrictionfactoralongthechanneltogetthesamefluxislargeforlargechanneltorsionataconstantrotation,andbecomessmallwhenthefavorablerotationoftherotortotheflowisapplied.Asforthesecondaryflowinacross-section,thereappearseveraltypesofvortex.Whenthereisnorotation,thesecondaryflowisalmostasymmetrictwo-vortextypeforsmallfluxasistheordinaryDeanvortex,butitchangestoafour-vortextypewhenthefluxislarge.Thesecondaryflowbecomesasymmetricastherotationisapplied.Wehaveunsteadyflowpatternsatlargefluxandrotation.

简介：Atopologymethodispresentedinthispapertorevealflowtructureoccurringinsieturbomachinery,inwhichnearwallflowstructureisrevealedbyusingwalllimitingstreamilinesandspaceflowfeatureisrevealedbyusingspacestreamilinesandcross-sectionstreamlines,Asanexample,acomputationalthree-dimensionalviscousflowfieldinsideatransonicturbinecascadeisstudied.Throughtheanalysis,theformandevolutionofvortexsystemandthewholeprocessofseparationoccurringwithinthiscascadearerevealed.Theapplicationoftopologymethodforanalyzeflowstructureinsideturbomachinmeryisveryimportantforunderstandingflowfeaturesandmechanismofflowlossevenforimprovingthedesignofturbomachineryandincreasingitsefficiency.

简介：这份报纸被奉献给考虑三维粘滞大规模空气的原始方程。首先，我们比那与更弱的起始的数据为原始方程证明全球well-posedness在[11]。第二，我们获得方程的光滑的答案的存在。而且，我们为大规模空气的原始方程产生的动态系统在V获得紧缩的全球引起注意的人，它改进结果[11]。

简介：在这篇论文，一有效多虚构边界方法(MFBM)结合了的格子女性的解答者包裹FEATFLOW被用于详细模拟不可压缩粘滞在至少一个动人的NACA0012机翼附近的流动。计算被继续fixedmultigrid液体方程到处在上满足的有限元素网孔，和机翼被允许通过网孔自由地移动。MFBM被采用对待在液体和机翼之间的相互作用。机翼的运动被Newton-Euler方程建模。实验的数字结果证实这个方法提供一个有效方法模仿不可压缩粘滞在动人的机翼附近的流动。

简介：Theprocessofsinteringofseveralparticlesincontactviaaviscousflowmechanismwasstudiednumericallyusingcomputationalfluiddynamics.Thevolumeoffluidtechniquewithinafinitevolumemethodwasusedtosimulatebridgeformationbetweenparticles,aswellasdensificationatdifferentconfigurationalstatesoftheparticles.Themethodwasvalidatedbycomparingresultsfortwo-particlecoalescencewiththeliterature.Theeffectofthenumberofparticlesonagglomerationkineticswasstudiedbycomparingbridgegrowthrateforsystemshavingdifferentnumbersofparticlesinachain.Althoughincreasingthenumberofparticlesledtoadecreaseinthelocalbridgegrowthrateandtoslowerequilibration,therewerenomarkeddifferences,whentheoverallvolumeofthesystemwasconsidered.Theeffectofcoordinationnumberonthedensificationratewasdirectlystudiedbychangingthenumberofparticlesincontactwithacentralparticle.Increasingthecoordinationnurnbeccausedtheoverallrateofdensificationtoincrease,butdelayedequilibration,analogoustostericeffects.Thesefindingsdescribetheconfigurationalstateofagglomerates,typicalofmesoscalecaking.Inamulti-scalestudy,theycanbeusedtocharacterizecakingatabulkscaletopartlyaddressthelackofexperimentaldatainthisfield.

简介：ThenumericalsolutionofincompressibleviscousflowoveranaerofoilisobtainedbyH-typegridsandaspecialdifferencescheme.Themethodofmassfluxcorectionisintroducedwithsuccessinordertoaccelerateconvergenceiniterationofvelocityandpressurecalculation.

简介：Basedonlinearized2-DNavier-Stokesequation,aLaplacetransform-boundaryelementcouplingmethodforviscousfluid-structureimpactanalysisisproposed.Underassumptionofincompressibilityforthefluid,thecorrespondingequivalentboundaryintegralequationintermsofthepotentialfunctionandstreamfunctionisfirstestablishedbyLamb’stransformintheLaplacetransformdomain.Itenablesustosolveim-pactwaterproblemsinfrequencydomainbytheboundaryelementmethod,inwhichtheeffectofviscousflowonthedynamicresponsecanbetakenintoaccount.Thenacompletesolutionoftheproblemunderconsider-ationintimedomainisobtainedbymeansofDurbin’sformulasforthenumericalinversionoftheLaplacetransform.Finally,apracticalexampleisgiventoconfirmthevalidityofthepresentmethod.

简介：AnewmethodbasedontheanisotropictensorforcefiniteelementandTaylor-Galerkinfiniteelementispresentedinthepresentpaper.Itsapplicationtotwo-dimensionalviscoustransonicflowinturbomachineryimprovestheconver-gencerateandstabilityofcalculation,andtheresultsobtainedagreewellwiththeexperimentalmeasurements.

简介：InteractionbetweentwosphereswithaninterstitialfluidisessentialinDiscreteElementmodelingforsimulatingthebehaviorsof'wet'particulatematerials.InthispapertheinteractionbetweentwosphereswithaninterstitialPower-lawfluidwasapproximatelyresolvedasnormalandtangentialinteractivemodelsrespectively,forwhichthegoverningequationsweresimplifiedonthebasisofReynoldsapproximation.Theseequationswerethensolvedanalyticallytogetherwiththeboundaryconditionstoobtainthepressuredistributionsforeachindividualmodel,andeventuallysolutionsoftheviscoussqueezeforceandthetangentialviscousresistancewereobtained,whichprovideasetofsolutionsforimplementingintoDEMcodeorotherpurposes.

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简介：Aboundaryelementmethodispresentedforthecoupledmotionanalysisofstructuralvibrationwithsmall-amplitudefluidsloshingintwo-dimensionalspace.ThelinearizedNavier-Stokesequationsareconsideredinfrequencydomainandtransformedintoboundaryintegralequations.AnappropriatefundamentalsolutionfortheHelmholtzequationwithpureimaginaryconstantisfound.Theconditionofzero-stressisimposedonthefreesurface,andnon-slipconditionoffluidparticlesisimposedonthewallsofthecontainer.Forrigidmotionmodels,theexpressionsforaddedmassandaddeddampingtothestructuralmotionequationsareobtained.Sometypicalnumericalexamplesarepresented.

简介：鳍和控制的运动出现在水下在液体的车辆是一个有趣、挑战性的研究题目。典型地在如此的身体附近的液体流动上的鳍摆动的效果是高度不稳定的，产生旋涡并且要求液体结构相互作用的详细分析。如此的流动的复杂性的理解在他们的推进开发能够高有活力的性能的车辆并且调遣的工程师感兴趣。在现在的学习，CFD基于搬进来的3-D鳍身体的RANS模拟一粘滞液体被开发。它由评估水动力学系数调查了水动力学性能(电梯，拖并且时刻)在二不同震荡频率。影响鳍身体的水动力学性能的因素的参量的分析被做，与从实验的结果的比较一起。模拟的结果在对试验性的结果的靠近的同意被发现，这为3-D鳍的不稳定的水动力学系数的评估作为一个有效工具验证了模拟。这个工作能是进一步的被用于稳定性的分析和激活的鳍的可操作性在水下车辆。

简介：为有状态的纬-法律气体方程的isentropicmagnetohydrodynamics(MHD)的二维的海军司烧方程，纬鈮?1，并且无限的电的抵抗力，我们执行分类可能的所有的全球分析粘滞吃惊侧面。精确，我们证明旅行波浪颂诗关于属类的阶段肖像由二个休息点连接了由的任何一个组成一粘滞宽松的侧面否则四休息指，二僵绳和二个节点。在后者配置，它休息，点被侧面连接取决于粘性，和罐头的比率包含宽松，overcompressive，或undercompressive吃惊侧面。考虑同样三维的答案，undercompressive震动是宽松类型的(Alfven)飘动。为单原子、两价的盒子纬=5/3和纬=7/5，与为无磁性的气体的标准粘性比率，我们数字地发现节点被侧面由把僵绳连接到节点的宽松的侧面围住的overcompressive的一个家庭连接，没有undercompressive震动发生。我们执行显示这些，二维的吃惊介绍的所有是线性地并且非线性地稳定的系统的数字Evans功能分析，关于二维、三维的不安。为一样的煤气的常数，而是不同粘性比率，我们也调查undercompressive震动为出现的案例；这些数字地被看见也稳定，关于二维并且(在到附近的Riemann答案的集中的中立意义)三维的不安。