Flow based oversampling technique for multiscale finite element methods

J. Chu, Yalchin Efendiev*, V. Ginting, T. Y. Hou

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Oversampling techniques are often used in porous media simulations to achieve high accuracy in multiscale simulations. These methods reduce the effect of artificial boundary conditions that are imposed in computing local quantities, such as upscaled permeabilities or basis functions. In the problems without scale separation and strong non-local effects, the oversampling region is taken to be the entire domain. The basis functions are computed using single-phase flow solutions which are further used in dynamic two-phase simulations. The standard oversampling approaches employ generic global boundary conditions which are not associated with actual flow boundary conditions. In this paper, we propose a flow based oversampling method where the actual two-phase flow boundary conditions are used in constructing oversampling auxiliary functions. Our numerical results show that the flow based oversampling approach is several times more accurate than the standard oversampling method. We provide partial theoretical explanation for these numerical observations.

Original languageEnglish (US)
Pages (from-to)599-608
Number of pages10
JournalAdvances in Water Resources
Volume31
Issue number4
DOIs
StatePublished - Apr 1 2008

Keywords

  • Finite volume
  • Multiscale
  • Oversampling
  • Two-phase flow
  • Upscaling

ASJC Scopus subject areas

  • Water Science and Technology

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