Coupled parallel flow through composite porous layers

In this work, we consider fluid flow through composite porous layers. The flow through the layers is either governed by the same flow model with different permeabilities, or by different models. In both cases, a matching condition at the interface between the layers is employed in the numerical solution of the flow problem. Finite difference expressions are derived for the interfacial velocity, and take into account the local truncation error, which is expressed as a function of the flow parameters and the step size employed.