Accession Number:

ADA453117

Title:

Shape Functions for Velocity Interpolation in General Hexahedral Cells

Descriptive Note:

Corporate Author:

COLORADO UNIV AT DENVER

Report Date:

2001-01-01

Pagination or Media Count:

23.0

Abstract:

Numerical methods for grids with irregular cells require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite-element CVMFE methods, vector shape functions approximate velocities and vector test functions enforce a discrete form of Darcys law. In this paper, a new vector shape function is developed for use with irregular, hexahedral cells trilinear images of cubes. It interpolates velocities and fluxes quadratically, because as shown here, the usual Piola-transformed shape functions, which interpolate linearly, cannot match uniform flow on general hexahedral cells. Truncation-error estimates for the shape function are demonstrated. CVMFE simulations of uniform and non-uniform flow with irregular meshes show first- and second-order convergence of fluxes in the L2 norm in the presence and absence of singularities, respectively.

Subject Categories:

  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE