Main Title |
General Mass-Conservative Numerical Solution for the Unsaturated Flow Equation. |
Author |
Celia, M. A. ;
Bouloutas, E. T. ;
Zarba, R. L. ;
|
CORP Author |
Princeton Univ., NJ. Dept. of Civil Engineering and Operations Research. ;Camp, Dresser and McKee, Inc., Boston, MA.;Robert S. Kerr Environmental Research Lab., Ada, OK.;Nuclear Regulatory Commission, Washington, DC.;National Science Foundation, Washington, DC. |
Publisher |
c1990 |
Year Published |
1990 |
Report Number |
NRC-04-88-074, NSF-8657419-CES; EPA/600/J-90/445; |
Stock Number |
PB91-177261 |
Additional Subjects |
Flow equations ;
Computational fluid dynamics ;
Partial differential equations ;
Numerical integration ;
Ground water ;
Approximation ;
Soils ;
Reprints ;
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB91-177261 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
16p |
Abstract |
The paper investigates the numerical behavior of standard approximation methods for the unsaturated flow equation. Solution using the h-based formulation and a backward Euler time discretization is shown to produce unacceptably large mass balance errors for many example calculations. This is true for any iteration method (Picard, Newton-Raphson, etc.). It is also true for both finite difference and finite element approximations in space, although finite elements are generally inferior to finite differences. A modified numerical approach is proposed that alleviates the mass balance problems discussed above. This approach is based on a fully implicit (backward Euler) time approximation applied to the mixed form of the unsaturated flow equation. |