Numerical study of mixed convection on jet impingement cooling in an open cavity filled with porous medium

The present study numerically investigates the opposing mixed convection arises from jet impingement cooling of a heated bottom surface of an open cavity in a horizontal channel filled with porous medium. The FeCrAlY foam is considered in the present study with a porosity of 0.867. The heat transfer characteristics are investigated with governing parameters in the range of Rayleigh number (50 <= 5Ra <= 150), Peclet number (1 <= 5Pe <= 1000) and dimensionless cavity depth (0 <= H <= 0.4). The results show that, the average Nusselt numbers decreases with the increase in dimensionless cavity depth. The opposing mixed convection is demonstrated to cause deterioration in average Nusselt number for fluid at certain Peclet number. The average Nusselt number for fluid is found to increase with the increase in Rayleigh number but the effect of Rayleigh number become insignificant at high Peclet number (Pe>500). (C) 2008 Elsevier Ltd. All rights reserved.