ABSTRACT

Petrov-Galerkin finite element models (PGFEMs) are frequently used because of their ability to provide oscillation-free results in simulating advective-dispersive transport of chemicals in the natural environment. PGFEMs, however, provide oscillation-free results at the expense of introducing significant artificial dispersion. The introduction of artificial dispersion may lead to erroneous model predictions in terms of both the arrival time and the peak concentrations. Specifically, model predictions may significantly overestimate the rate at which the leading edge of a contaminant plume moves in the direction of flow and underestimate the peak concentration monitored at a given point in space. Traditional PGFEMs, generally, introduce excess artificial dispersion into their solution procedures than necessary in order to ensure numerical stability. The objective of this paper is to present an optimized PGFEM (OPGFEM) that minimizes artificial dispersion and provides relatively accurate model predictions over a wider range of Peclet numbers.