Numerical investigation of pressure drop reduction without surrendering heat transfer enhancement in partially porous channel

The present study is to investigate the numerical simulation of steady laminar forced convection in a partially porous channel, with four dissimilar porous-blocks, attached to the strip heat sources at the bottom wall. The analysis is based on the Navier-Stokes equation in the fluid field, the Darcy-Brinkman-Forchheimer flow model in the porous field, and the energy equations for two thermal fields. The effects of variations of different parameters such as porous blocks Darcy numbers, arrangements of dissimilar blocks, Forchheimer coefficient, Reynolds number, thermal conductivity and Prandtl number are investigated and the velocity and temperature fields are presented and discussed. In the dissimilar partially porous channel, it is found that when the blocks sorted from the lowest to the highest Da in the flow direction, the total heat transfer enhancement is almost the same as in the similar porous channel (Nu/Nu(sim) = 92%), while the total pressure drop is considerably lower (P/P-sim = 28%). In addition, reverse arrangement of porous blocks is suggested to prepare more uniform temperature gradient in all heat sources. (C) 2010 Elsevier Masson SAS. All rights reserved.