Accession Number:

ADA445725

Title:

Shape Functions for Three-Dimensional Control-Volume Mixed Finite-Element Methods on Irregular Grids

Descriptive Note:

Conference paper

Corporate Author:

GEOLOGICAL SURVEY DENVER CO

Report Date:

2002-01-01

Pagination or Media Count:

9.0

Abstract:

Numerical methods based on unstructured grids, with irregular cells, frequently require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells. Previous, two-dimensional developments used linear shape functions to interpolate velocities within a quadrilateral cell. For irregular hexahedral cells in three dimensions, it can be shown that linear shape functions cannot exactly represent the flux distribution across a cell under uniform flow conditions. As a result, uniform flow cannot be exactly simulated. A new vector shape function is proposed for use with irregular hexahedral cells that should provide for a more accurate velocity approximation within a cell. This velocity shape function is a non-linear interpolator, containing quadratic terms.

Subject Categories:

  • Numerical Mathematics
  • Fluid Mechanics
  • Hydrology, Limnology and Potamology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE