Simulation and analytical validation of forced convection inside open-cell metal foams

Abstract

Two ideal three-dimensional geometries are generated using cylinder-joint and sphere-subtraction methods, respectively. The former is firstly used to establish simple geometrical relations among average pore diameter, strut diameter, ligament diameter, porosity, and specific surface area. An analytical model of heat transfer in a foamed heat exchanger is then proposed using the transfer matrix method and one-equation model. The heat transfer predictions have been compared with available experimental data and favorable agreements have been obtained. Heat transfer coefficient and pressure drop in both two geometries with different porosities and cell dimensions are investigated using COMSOL Multiphysics. Pressure drop verifications among numerical results, semi-empirical models, and experimental data show good feasibility of Kelvin structure. The proposed Kelvin geometric model is shown to be self-consistency with respect to both its geometrical characteristics and thermal properties, which can be adopted for finer details of pressure drop phenomenon.