简介:Inthispaper,someeffectivecascadicmultigridmethodsareproposedforsolvingthelargescalesymmetricornonsymmetricalgebraicsystemsarisingfromthefinitevolumemethodsforsecondorderellipticproblems.Itisshownthatthesealgorithmsareoptimalinbothaccuracyandcomputationalcomplexity.Numericalexperimentsarereportedtosupportourtheory.
简介:Inthispaper,weconstructandanalyseamortarfinitevolumemethodforthediscretizationforthebiharmonicprobleminR2.Thismethodisbasedonthemortar-typeAdininonconformingfiniteelementspaces.TheoptimalorderH2-seminormerrorestimatebetweentheexactsolutionandthemortarAdinifinitevolumesolutionofthebiharmonicequationisestablished.
简介:Inthispaper,finitevolumemethodonunstructuredmeshesisstudiedforaparabolicconvection-diffusionproblemonanopenboundedsetofR^d(d=2or3)withRobinboundarycondition.UpwindingapproximationsareadaptedtotreatboththeconvectiontermandRobinboundarycondition.Bydirectlygettingstartfromtheformulationofthefinitevolumescheme,numericalanalysisisdone.Byusingseveraldiscretefunctionalanalysistechniquessuchassummationbyparts,discretenorminequality,etal,thestabilityanderrorestimatesontheapproximatesolutionareestablished,existenceanduniquenessoftheapproximatesolutionandthe1stordertemporalnormandL^2andH^1spacialnormconvergencepropertiesareobtained.
简介:Anunstructuredmeshfinitevolumediscretisationmethodforsimulatingdiffusioninanisotropicmediaintwo-dimensionalspaceisdiscussed.Thistechniqueisconsideredasanextensionofthefullyimplicithybridcontrol-volumefinite-elementmethodanditretainsthelocalcontinuityofthefluxatthecontrolvolumefaces.Aleastsquaresfunctionrecon-structiontechniquetogetherwithanewfluxdecompositionstrategyisusedtoobtainanaccuratefluxapproximationatthecontrolvolumeface,ensuringthattheoverallaccuracyofthespatialdiscretisationmaintainssecondorder.Thispaperhighlightsthatthenewtechniquecoincideswiththetraditionalshapefunctiontechniquewhenthecorrectiontermisneglectedandthatitsignificantlyincreasestheaccuracyofthepreviouslinearschemeoncoarsemesheswhenappliedtomediathatexhibitverystrongtoextremeanisotropyratios.Itisconcludedthatthemethodcanbeusedonbothregularandirregularmeshes,andappearsindependentofthemeshquality.