Thermal Performance Analysis of Bi-Porous Metal Foam Heat Sink

Abstract

The three-dimensional forced convective heat transfer in a bi-porous metal foam heat sink is numerically investigated. Each of the metal foam layers has a distinct thickness, porosity, and pore density. The effects of these geometrical and morphological parameters on fluid flow and heat transfer are analyzed by employing the Forchheimer-Brinkman extended Darcy momentum equation and local thermal non-equilibrium energy equation. The numerical results show that the thermal resistance of the bi-porous metal foam heat sink is decreased with reduction in top layer metal foam porosity, as well as the bottom layer metal foam thickness, for a fixed bottom metal foam porosity of 0.9. The best thermal performance is achieved by employing a 30PPI metal foam at the bottom layer, and a 50PPI metal foam at the top layer. The optimal thickness of the bottom foam layer is about 1mm.