Experimental and numerical investigation of forced convection heat transfer of air in non-sintered porous media

Forced convection heat transfer of air in plate channels filled with glass or non-sintered steel spherical particles was investigated experimentally and numerically. The effects of thermal dispersion, variable properties caused by the pressure variation, particle diameter, particle thermal conductivity and fluid velocity were studied. The experimental results and numerically calculated values for the friction factor in porous media agree well with established formula. The porous media significantly increased the pressure drop in the plate channel compared to an empty channel. The non-sintered porous media enhanced the heat transfer by 4-8 times for the conditions studied, which was much less than the enhancement due to the sintered porous media due to the contact thermal resistance in the non-sintered porous media. The heat transfer coefficient decreased with smaller glass particle diameters and increased with the particle thermal conductivity. The influence of the solid particle thermal conductivity on the convection heat transfer of air in porous media decreased as the solid particle thermal conductivity decreased. Numerical simulation results with the local thermal non-equilibrium model with consideration of thermal dispersion corresponded well to the experimental data for both glass and metallic porous structures. The effects of pressure variation on the convection heat transfer was less important. (C) 2003 Elsevier Inc. All rights reserved.