A SECOND ORDER CONTROL-VOLUME FINITE-ELEMENT LEAST-SQUARES STRATEGY FOR SIMULATING DIFFUSION IN STRONGLY ANISOTROPIC MEDIA

(整期优先)网络出版时间:2005-01-11
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Anunstructuredmeshfinitevolumediscretisationmethodforsimulatingdiffusioninanisotropicmediaintwo-dimensionalspaceisdiscussed.Thistechniqueisconsideredasanextensionofthefullyimplicithybridcontrol-volumefinite-elementmethodanditretainsthelocalcontinuityofthefluxatthecontrolvolumefaces.Aleastsquaresfunctionrecon-structiontechniquetogetherwithanewfluxdecompositionstrategyisusedtoobtainanaccuratefluxapproximationatthecontrolvolumeface,ensuringthattheoverallaccuracyofthespatialdiscretisationmaintainssecondorder.Thispaperhighlightsthatthenewtechniquecoincideswiththetraditionalshapefunctiontechniquewhenthecorrectiontermisneglectedandthatitsignificantlyincreasestheaccuracyofthepreviouslinearschemeoncoarsemesheswhenappliedtomediathatexhibitverystrongtoextremeanisotropyratios.Itisconcludedthatthemethodcanbeusedonbothregularandirregularmeshes,andappearsindependentofthemeshquality.