Abstract
In this paper, a two‐dimensional two‐phase mathematical model based on Darcy's law and conservation of mass for each liquid is presented. The numerical model is based on a generalized method of weighted residuals in conjunction with the finite element method and linear quadrilateral isoparametric elements. To alleviate numerical problems associated with hyperbolic equations, upstream weighting of the spatial terms in the model has been incorporated. The theoretical and numerical accuracy of the model is verified by comparison of simulation results with those from an existing one‐dimensional two‐phase flow simulator. The finite element model is used to simulate the migration of an immiscible organic solvent in groundwater, from a chemical waste disposal site located north of Niagara Falls, New York. The effects of uncertainty regarding porous media heterogeneities and anisotropy are examined, and it is concluded that the extent of immiscible contaminant migration is greatly sensitive to these parameters.