Numerical investigation of heat transfer and fluid flow behaviors of a block type graphite foam heat sink inserted in a rectangular channel

Abstract

In the present study, forced convection in a rectangular channel filled by a block of graphite foam is numerically investigated. A two energy equation model with the Brinkman-Forchheimer extended Darcy model is considered in the numerical investigation. A parametric study for the ranges of Re = 813–10,582 and L/H = 1–2 is carried out to examine the thermal (Nux and Nuave) and the fluid flow (Δp) behaviors of a heat sink made of graphite foam. Additionally, the heat removal and fluid flow performances of the block type graphite foam insert are compared with that of aluminum foam with the aim of demonstrating its superiority and deficit points. It is found that the plug flow conditions are valid inside both graphite and aluminum foam heat sinks. The graphite foam heat sink has a better heat transfer performance with a larger pressure drop when it is compared with aluminum foam heat sink. A significant temperature difference between the solid and gas phases inside the graphite foam heat sink is noticed over the ranges of conditions tested. The numerical code used in this study is verified by the existing experimental data and a good agreement is observed between them.