Abstract:

The process of controlledrelease and spread of a solute in porous media contains three physical processes: the process of release of the solute into the porous media through the border of the film, the flow of fluid and the process of the  spread of the solute in porous media. The process of controlledrelease was governed by a boundary integralordinary differential equation, while the process of spread was characterized by a convectiondiffusion (with mechanical dispersion)equation with a boundary condition of the third type in the unknown velocity field, which follows Darcy′s law. A mixed finite elementGalerkin finite element scheme was proposed for solving the coupled nonlinear systems.Convergence was analyzed by a priori estimate method.

Key words: mixed finite element method; controlledrelease; porous medium; error estimate