Numerical Study of Jet Impingement on Heated Sink Covered by a Porous Layer

Abstract

This numerical study aims to enhance the heat transfer efficiency by dissipating the heat Emitted from electronic processors. A jet impingement technique is utilized with porous layer covering a metal fin as a heat sink. Forced convection and normal convection (due to the buoyancy effect) are taken into consideration. The two equations model (Local Thermal Non-Equilibrium LTNE) employed to describe the energy equations of the two phases of the porous surface. Finite Element Method (FEM) used to discretize these equations to obtain the numerical solution. To make this study closest to the reality, constant heat flux boundary condition is applied underneath the metallic heat sink. The geometry comprises of three domains: Free flow channel, Porous layer and Metal fined heat sink. In order to simulate the heat transfer, isotherms; streamlines and Nusselt number have been considered. Investigation has been done by inspecting the effects of the pertinent non-dimensional parameters such as: Reynolds number (Re = 100-900), Darcy number (Da = 10-1-10-6), Richardson number (Ri = 0.1-100) and Porosity (ε = 0.85-0.95). The results show that increasing Re and decreasing ε lead to enhance Nusselt number. Richardson number below 100 has no significant effects on Nu. At Re above 400, Nusselt number proportional with Darcy number. The enhancement of Nusselt number is found to be 250 % by increasing Re from 100 to 900, 290 % by decreasing ε from 0.95 to 0.85 and about 13 % by increasing Darcy number from 10-6 to 10-1.