Experimental investigation of flow assisted mixed convection in high porosity foams

This paper reports the results of an experimental study on flow assisted mixed convection in aluminium metal foams of different pores per inch (PPI) with high porosity in the range of 0.9 to 0.95. With a view to delineate the flow regimes, experiments are conducted for Richardson number (Ri) range of [0.001≤Ri≤700J. Based on a parametric study with a large number of experimental data, a correlation for Nusselt number of the porous medium as a function of Richardson number, Peclet number, and the porosity is developed. In order to quantify the enhancement of the heat transfer rate with the use of porous medium, correlations for (i) Nusselt number and (ii) ratio of heat transfer rate with and without porous medium have also been developed. The enhancement ratio is always more than one which clearly indicates that metal foams have good heat transfer enhancement capability.