Accession Number : ADA324497

Title :   Control-Volume Mixed Finite Element Methods.

Descriptive Note : Contract rept.,

Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s) : Jones, J. E. ; Cai, Z. ; McCormick, S. F. ; Russell, T. F.

PDF Url : ADA324497

Report Date : FEB 1997

Pagination or Media Count : 29

Abstract : A key ingredient in simulation of flow in porous media is accurate determination of the velocities that drive the flow. Large-scale irregularities of the geology (faults, fractures and layers) suggest the use of irregular grids in simulation. This paper presents a control-volume mixed finite element method that provides a simple, systematic, easily implemented procedure for obtaining accurate velocity approximations on irregular block-centered grids. The control-volume formulation of Darcy's law can be viewed as a discretization into element-sized tanks with imposed pressures at the ends, giving a local discrete Darcy law analogous to the block-by-block conservation in the usual mixed discretization of the mass-conservation equation. Numerical results in two dimensions show second-order convergence in the velocity, even with discontinuous anisotropic permeability on an irregular grid. The method extends readily to three dimensions.

Descriptors :   *FINITE ELEMENT ANALYSIS, *FLOW FIELDS, COMPUTERIZED SIMULATION, TWO DIMENSIONAL, GRIDS, COMPUTATIONAL FLUID DYNAMICS, APPROXIMATION(MATHEMATICS), PARTIAL DIFFERENTIAL EQUATIONS, CONVERGENCE, APPLIED MATHEMATICS.

Subject Categories : Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE