A new prediction model for the effective thermal conductivity of high porosity open-cell metal foams

Abstract

In this paper, a new prediction model for the effective thermal conductivity (ETC) of high porosity open-cell metal foams is proposed by introducing the concave tri-prism foam ligament to the tetrakaidecahedron-based foam cell structure as well as considering the effects of ligament orientation and filling medium. The proposed model can avoid using the non-universal empirical parameter that has to be determined experimentally. For validation of the present model, the ETC measurements of copper foams saturated with air, water and paraffin, which are rarely reported in the literature, are also conducted in this work. These ETC data of copper foams, along with the ETC measurements of aluminum and nickel foams from the literature, are used to validate the present model. It shows that the present model, when compared with other ETC models reported in the literature, can better predict the ETC experimental results of high porosity metal foam, with the average prediction deviations for different metal foams (copper, aluminum and nickel foams) saturated with different mediums (air, water and paraffin) within 10%, which can be attributed to the adoption of relatively realistic foam structure and simultaneous consideration of the ligament orientation and filling medium effects in the present model.