Experimental Verification of Darcy-Brinkman-Forchheimer Flow Model for Natural Convection in Porous Media

Experimental results for natural convection in a horizontal porous cavity of aspect ratio, A = 5, and heated from below are reported. A wide range of governing parameters are covered by careful selection of beads size, solid material, and fluid. These results fully support the effects of fluid flow parameters (Rayleigh and Prandtl numbers), porous matrix structure parameters (Darcy and Forchheimer numbers), and the conductivity ratio as predicted by the formulation based on the Darcy-Brinkman-Forchheimer (DBF) equations of motion. The DBF flow model, with variable porosity and variable thermal conductivity in the wall regions, predicts reasonably well in comparison with the experimental data. However, the difference between the predictions and the measurements increases as the ratio of solid-to-fluid thermal conductivity becomes very large.