View article

An Eulerian‐Lagrangian localized adjoint method (ELLAM) numerical solution is developed for the multiphase contaminant transport equations in two dimensions. The ELLAM uses finite volume test functions in the space‐time domain defined by the characteristics of the hyperbolic part of the governing equation. The use of the characteristics results in an approximation that allows large time steps while still maintaining accurate solutions. This greatly reduces the computational effort required to find solutions to the advection‐dispersion equation. Combination of the finite volume test functions with the conservative form of the governing equation results in a local conservation of mass property. For problems with a constant saturation such as that of contaminant transport in the saturated zone this property is highly advantageous as the resulting numerical approximation conserves mass both globally and locally. For …