Natural convection in a vertical channel with open-cell foams

Abstract

Open-cell foams are promising to enhance heat transfer in many applications, such as electronics cooling. Though heat transfer coefficients are low, natural convection in open-cell foams is used in low-end applications, as consumer electronics or switching devices. In this paper air natural convection in a vertical channel equipped with an open-cell foam, with a symmetric uniform heat flux boundary condition at the vertical sides, is investigated numerically. The foam is modeled as a continuous porous medium under the assumption of Local Thermal Non-Equilibrium (LTNE) between solid and fluid phases. Mass, momentum and energy equations are solved numerically under the appropriate boundary conditions by employing a commercial finite element code. The velocity of the fluid and the temperature of the solid as well as the global heat transfer coefficient, for different thermo-physical properties and morphologies of the foam, and for various channel aspect ratios, are predicted.