Forced convection cooling enhancement by use of porous materials

Results are presented for laminar forced convection cooling of heat generating blocks mounted on a wall in a parallel plate channel. The effect on heat transfer of insertion of a porous matrix between the blocks is considered. The flow in the porous medium is modeled using the Brinkman-Forchheimer extended Darcy model. The mass, momentum and energy equations are solved numerically by a control-volume-based procedure. The local Nusselt number at the walls of the blocks, the mean Nusselt numbers and the maximum temperature in the blocks are examined for a wide range of Darcy number and thermal conductivity ratio. The computations are first conducted for a single block, then for evenly mounted blocks. The results show that the insertion of a porous material between the blocks may enhance the heat transfer rate on the vertical sides of the blocks. Although the porous matrix reduces the heat transfer coefficient on the horizontal face, significant increases in the mean Nusselt number (up to 50%) are predicted and the maximum temperatures within the heated blocks are reduced in comparison with the pure fluid case.