Conjugate natural convection in an open-ended porous square cavity

Conjugate natural convection-conduction heat transfer in an open-ended porous square cavity with a finite wall thickness is studied numerically in the present article for a wide variety of thermal boundary conditions. The Forchheimer- Brinkman-extended Darcy model is used in the mathematical formulation for the porous layer, and the COMSOL is applied to solve the dimensionless governing equations. The governing parameters considered are the Rayleigh number (10³ ≤ Ra ≤ 10⁶), the porosity of the porous medium (0:4 ≤ ε ≤ 0:99), the wall-to-porous medium conductivity ratio (0:1 ≤ Kr ≤ 10:0), and the ratio of wall thickness to its width (0:02 ≤ D ≤ 0:4). The results are presented to show the effect of these parameters on the fluid flow and heat-transfer characteristics. The fluid in the bottom cavity was found stagnant at the relative low- and moderate-conductivity ratio for a case heating from above. It is also found that decreasing the thickness of the solid wall and/or increasing the porosity increases the flow circulation and the heat transfer for the various conductivity ratios and several thermal configurations.