Mixed Convection Cooling of Heat Sources Mounted with Porous Blocks

摘要

A numerical study is performed to analyze laminar mixed convection in a parallel-plate vertical channel with discrete strip heat sources on one channel wall. The effect on heat transfer of a porous block mounted above each heat source is considered. The Brinkman-Forchheimer-Extended Darcy model with the Boussinesq approximation is used to characterize the flowfield inside the porous region. Solution of the coupled governing equations for the porous/fluid composite system is obtained by utilizing a control volume method through the use of a stream function-vorticity approach. The characteristics of fluid flow and mixed convection heat transfer have been obtained by the examination of various governing parameters such as the Darcy number, Reynolds number, inertia parameter, Grashof number, conductivity ratio, and geometric parameter. The results indicate that the size and strength of recirculating flow induced by the porous block make significant changes in the cooling of strip heater, especially at both trailing and leading edges of heaters. In addition, it is shown that specific choices in porous block shape, permeability, and thermal conductivity can produce profound effects on the flow and heat transfer characteristics.