Modeling gas-phase flow in porous media

In this communication, the equations and methodology for modeling convection and both ordinary and Knudsen diffusion of gases in a porous medium are described. Parallels between our development and that of the dusty-gas model are made. Our derivation results in a self-consistent description of the various transport mechanisms and is more robust for numerical solutions, especially for conditions involving different flow regimes or where the regime is not known a priori. Along with the equation development, some limiting cases are examined and discussed with respect to the benefits and differences of our methodology versus that of the dusty-gas model.