Examples of numerical simulations of two- dimensional unsaturated flow with VS2DI code using different interblock conductivity averaging schemes

Loading...
Thumbnail Image

Date

2015-09

Advisor

Editor

Journal Title

Journal ISSN

Volume Title

Publisher

Instytut Geologii UAM

Title alternative

Abstract

Flow in unsaturated porous media is commonly described by the Richards equation. This equation is strongly nonlinear due to interrelationships between water pressure head (negative in unsaturated conditions), water content and hydrau- lic conductivity. The accuracy of numerical solution of the Richards equation often depends on the method used to estimate average hydraulic conductivity between neighbouring nodes or cells of the numerical grid. The present paper discusses application of the computer simulation code VS2DI to three test problems concerning infiltration into an ini- tially dry medium, using various methods for inter-cell conductivity calculation (arithmetic mean, geometric mean and upstream weighting). It is shown that the influence of the averaging method can be very large for coarse grid, but that it diminishes as cell size decreases. Overall, the arithmetic average produced the most reliable results for coarse grids. Moreover, the difference between results obtained with various methods is a convenient indicator of the adequacy of grid refinement.

Description

Sponsor

Keywords

numerical modelling, Richards equation, hydraulic conductivity

Citation

Geologos, 2015, 21, 3. s.161-167

Seria

ISBN

978-83-232187-4-6

ISSN

1426-8981

DOI

Title Alternative

Rights Creative Commons

Creative Commons License

Uniwersytet im. Adama Mickiewicza w Poznaniu
Biblioteka Uniwersytetu im. Adama Mickiewicza w Poznaniu
Ministerstwo Nauki i Szkolnictwa WyĆŒszego