On Galerkin models for transport in groundwater

The Galerkin finite element model (GFEM) may provide oscillatory results wh en employed to predict contaminant transport in groundwater unless a very f ine mesh is used. Adaptation of a very line mesh may make the application o f the GFEM impractical to field problems. The Petrov-Galerkin finite elemen t models (PGFEMs) can provide oscillation free results for relatively coars er mesh. However, the PGFEM violates the Galerkin principle and introduces large "numerical" dispersion. The objective of this paper has been to devel op accurate criteria to improve the applicability of the GFEM to obtain osc illation free accurate results for coarser mesh and compare its performance with that of the PGFEM. It has been shown that the GFEM provides oscillati on free accurate results for coarser mesh with Peclet number Pe less than o r equal to 20. Further, the GFEM prediction has always been more accurate t han the PGFEM for a variety of source configurations and flow fields. (C) 1 999 Elsevier Science Inc. All rights reserved.