简介：Severalquadrilateralshaperegularmeshconditionscommonlyusedinthefiniteelementmethodareproventobeequivalent.Theirinfluenceonthefiniteelementinterpolationerrorandtheconsistencyerrorcommittedbynonconformingfiniteelementsareinvestigated.TheeffectoftheBi-SectionConditionanditsextendedversion(1+α)-SectionConditiononthedegeneratemeshconditionsisalsochecked.ThenecessityoftheBi-SectionConditioninfiniteelementsisunderpinnedbymeansofcounterexamples.

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简介：我们在场突然地重建的削尖的途径展示从的一个柔韧的网孔相配或chamfered特征，甚至与噪音和aliasing错误。特征区域首先根据用户的输入经由正常变化被认出，然后过滤的正常被用于特征区域的脸。最后，特征区域的顶点逐渐地用一个最少平方的错误标准基于新面孔正常被更新。试验性的结果证明方法在削尖有效、柔韧网孔。

简介：不同液体的混乱混合生产旋绕的结构到分开这些液体的接口。为能溶合的液体(是这里考虑了)，这个接口被定义为50%集体集中isosurface。为导致的冲击波(Richtmyer-Meshkov)不稳定性，我们发现接口当计算网孔被精制，逐渐地复杂。如果Kolmogorov规模相对网孔是小的，这界面的混乱被粘性，或由计算网孔割掉。在集成的接口统计的政体，我们然后检验混合，即集中统计，由质量调整了散开。为比统一显著地大的Schmidt数字，典型地代表液体或稠密的血浆，另外的网孔精炼通常被需要克服数字集体散开并且完成混合问题的一个集成的答案。然而，与前面追踪的利益并且与一个算法，那允许有限接口散开，我们能在Schmidt数字一致地保证集中。我们证明不同答案源于Schmidt数字的变化。我们建议潜水艇格子粘性和可能在现实主义的格子层次允许集成的答案的集体散开parameterizations。

简介：Solution-drivenmeshadaptationisbecomingquitepopularforspatialerrorcontrolinthenumericalsimulationofcomplexcomputationalphysicsapplications,suchasclimatemodeling.Typically,spatialadaptationisachievedbyelementsubdivision(hadaptation)withaprimarygoalofresolvingthelocallengthscalesofinterest.Asec-ond,less-popularmethodofspatialadaptivityiscalled'meshmotion'(radaptation);thesmoothrepositioningofmeshnodepointsaimedatresizingexistingelementstocapturethelocallengthscales.Thispaperproposesanadaptationmethodbasedonacombinationofbothelementsubdivisionandnodepointrepositioning(rhadaptation).Bycombiningthesetwomethodsusingthenotionofamobilityfunction,theproposedapproachseekstoincreasetheflexibilityandextensibilityofmeshmotionalgorithmswhileprovidingasomewhatsmoothertransitionbetweenrefinedregionsthanispro-ducedbyelementsubdivisionalone.Further,inanattempttosupporttherequirementsofaverygeneralclassofclimatesimulationapplications,theproposedmethodisde-signedtoaccommodateunstructured,polygonalmeshtopologiesinadditiontothemostpopularmeshtypes.

简介：Anewmeshfreemethodproposedbytheauthorswaspresented,inwhichthederivativesateachnodewereconstructedusingwholederivativeformulasthroughthenodesselectedaroundthenodeusinglocalCartesianframeinanautonomousmanner,sothatwithoutanyelementitcouldbeconsideredasacompletelymeshfreemethod.Themethodwastestedwithanumericalexample,andreliablesolutionwasobtainedwithhighaccuracyandefficiency.

简介：Wepresentanovelalgorithmforadaptivetriangularmeshcoarsening.Thealgorithmhastwostages.First,theinputtriangularmeshisrefinedbyiterativelyapplyingtheadaptivesubdivisionoperatorthatperformsaso-calledred-greensplit.Second,therefinedmeshissimplifiedbyaclusteringalgorithmbasedoncentroidalVoronoitessellations(CVTs).TheaccuracyandgoodqualityoftheoutputtriangularmeshareachievedbycombiningadaptivesubdivisionandtheCVTstechnique.Testresultsshowedthemeshcoarseningschemetoberobustandeffective.Examplesareshownthatvalidatethemethod.

简介：Withthedevelopmentofadvancedimagingtechnology,digitalimagesarewidelyused.Thispaperproposesanautomaticquadrilateralmeshgenerationalgorithmformulti-colourimagedstructures.Ittakesanoriginalarbitrarydigitalimageasaninputforautomaticquadrilateralmeshgeneration,thisincludesremovingthenoise,extractingandsmoothingtheboundarygeometriesbetweendifferentcolours,andautomaticall-quadmeshgenerationwiththeaboveboundariesasconstraints.Anapplicationexampleis...

简介：为解决一个维的时间检验动人的网孔方法依赖部分微分方程。微分代数学的明确的表达的介绍基于几何变量；数字途径的well-posedness的调查；某详细数字过程的讨论。

简介：我们在解决高原网孔问题分析三通常使用的精力功能，也就是说Dirichlet，区域，和分离吝啬的弯曲(直接数字控制)。他们都与其它相比拥有唯一的优点，但是他们的缺点个别地限制他们的用法。我们的算法一起联合三步充分利用他们的特征。起初，Dirichlet精力与更好的拓扑学为更快的近似被优化。然后，区域精力被用来接近抑制领域。最后，DMC精力订婚完成更好收敛的步。结果证明我们的方法能在一个相当吵闹的起始的网孔下面工作，它与最后的结果甚至拓扑地不同。

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简介：Thispaperpresentsanefficientmovingmeshmethodtosolveanonlinearsingularproblemwithanoptimalcontrolconstrainedcondition.ThephysicalproblemisgovernedbyanewmodelofturbulentflowincirculartubesproposedbyLuoetal.usingPrandtl'smixing-lengththeory.Ouralgorithmisformedbyanouteriterativealgorithmforhandlingtheoptimalcontrolconditionandaninneradaptivemeshredistributionalgorithmforsolvingthesingulargoverningequations.Wediscretizethenonlinearproblembyusingaupwindingapproach,andtheresultingnonlinearequationsaresolvedbyusingtheNewton-Raphsonmethod.Themeshisgeneratedandthegridpointsaremovedbyusingthearc-lengthequidistributionprinciple.Thenumericalresultsdemonstratethatproposedalgorithmiseffectiveincapturingtheboundarylayersassociatedwiththeturbulentmodel.

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简介：Inthispaper,anewmethodoftopologicalcleanupforquadrilateralmeshispresented.Themethodfirstselectsapatchofmesharoundanirregularnode.Itthenseeksthebestconnectionoftheselectedpatchaccordingtoitsirregularvalenceusinganewtopologicaloperation:smallpolygonreconnection(SPR).Byreplacingtheoriginalpatchwithanoptimalonethathaslessirregularvalence,meshqualitycanbeimproved.Threeapplicationsbasedontheproposedapproachareenumerated:(1)improvingthequalityofaquadrilateralmesh,(2)convertingatriangularmeshtoaquadrilateralone,and(3)adaptingatrianglegeneratortoaquadrilateralone.Thepresentedmethodishighlyeffectiveinallthreeapplications.

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简介：AnewapproachfortreatingthemeshwithLagrangianschemeoffinitevolumemethodispresented.IthasbeenprovedthatclassicalLagrangianmethodisdifficulttocopewithlargedeformationintrackingmaterialparticlesduetoseveredistortionofcells,andthechangingconnectivityofthemeshseemsespeciallyattractiveforsolvingsuchissues.Themeshwithlargedeformationbasedoncomputationalgeometryisoptimizedbyusingnewmethod.Thispaperdevelopsaprocessingsystemforarbitrarypolygonalunstructuredgrid,theintelligentvariablegridneighborhoodtechnologiesisutilizedtoimprovethequalityofmeshincalculationprocess,andarbitrarypolygonalmeshisusedintheLagrangianfinitevolumescheme.Theperformanceofthenewmethodisdemonstratedthroughseriesofnumericalexamples,andthesimulationcapabilityisefficientlypresentedincopingwiththesystemswithlargedeformations.

简介：Anadaptivemeshfiniteelementmodelhasbeendevelopedtopredictthecrackpropagationdirectionaswellastocalculatethestressintensityfactors(SIFs),underlinear-elasticassumptionformixedmodeloadingapplication.Thefiniteelementmeshisgeneratedusingtheadvancingfrontmethod.Inordertosuittherequirementsofthefractureanalysis,thegenerationofthebackgroundmeshandtheconstructionofsingularelementshavebeenaddedtothedevelopedprogram.Theadaptiveremeshingprocessiscarriedoutbasedontheposterioristresserrornormschemetoobtainanoptimalmesh.Previousworksoftheauthorshaveproposedtechniquesforadaptivemeshgenerationof2Dcrackedmodels.Facilitatedbythesingularelements,thedis-placementextrapolationtechniqueisemployedtocalculatetheSIF.Thefractureismodeledbythesplittingnodeapproachandthetrajectoryfollowsthesuccessivelinearextensionsofeachcrackincrement.TheSIFsvaluesfortwodifferentcasestudieswereestimatedandvalidatedbydirectcomparisonswithotherresearcherswork.

简介：Thereliabilityandaccuracyofnumericalresultsofmicroparticlefluidizationinaconicalbed,affectedsimultaneouslybymeshrefinement,thegridconfigurationandthewallboundarycondition(BC),areanalyzed.Specifically,pressuregradientsandvelocityprofilesoftitaniapowderarestudiedforaconicalbed.TheGidaspowdragcorrelationanddifferentwallBCsareconsideredusingaEulerian-Euleriantwo-fluidmodel.Predictionsofthepressurefluctuation,powerspectraofthecorrespondingpressurefluctuations,bedpressuredrop,minimumfluidizationvelocity,axialsolidvelocity,bedexpansionratio,andparticlesizedistributionarecomparedwithexperimentaldata.Meshsensitivityanalysisusinghexahedralandtetrahedralcellswithauniformmeshandnear-wallmeshrefinemenrisconductedtoinvestigatetheeffectsofmeshconfigurationsinestimatingparticleflowpatterns.Simulationsshowthatsignificantsavingsintermsofcomputationaltimearerealizedbychoosingauniformmeshwhilethehexahedralstructure,thenear-wallmeshrefinement,andthefree-slipBCgivetheclosestfittotheexperimentaldata.