Finite element model and experimental comparison of coupled free-channel-porous-media flow

Concurrent free and porous medium domain flows are common in many naturally occurring phenomena and industrial fluid processes. Mathematical models for these coupled domain flows must maintain the continuity of properties across the boundaries between the domains for consistency with the physics of the process. A finite element (FE) approach is applied using a commercial partial differential equation solver (FlexPDE^TM) to simulate a coupled domain flow system. This work demonstrates a feasible and effective approach to model coupled free channel and porous medium flows over a wide range of permeabilities. Experiments were conducted to verify the simulation model. The model was applied in a parametric study to determine the permeability values in the porous medium when the Darcy term in the Brinkman equation dominates over the viscous dissipation term and when both Darcy and viscous flow terms are significant.