Analytical Determination of the Geometrical Properties of Open-Celled Metal Foams Under Compression

Abstract

Abstract. Several studies in the literature have been devoted to the permeability prediction of metal foams, including that involving the Representative Unit Cell (RUC) model. The RUC modelling approach is an attractive modelling method due to the simple rectangular geometry, as well as its satisfying performance in comparison to other models and experimental data as proven elsewhere in the literature for porous media. The subject of compression of metal foams has been addressed elsewhere in the literature, but this study is the first to involve an all-inclusive analytical model where both streamwise and transverse compression are accounted for. The Darcy and Forchheimer permeability coefficients of the compressed foam (or three-strut) RUC model are presented. Furthermore, a geometric approach requiring measured geometric parameters and a combined geometric-kinetic approach involving measured permeability coefficients are included for determining the specific surface area. Geometric parameters required to determine the permeability and specific surface area predictions using the compressed foam RUC model include the uncompressed porosity, pore dimension and strut diameter, as well as the compression factor. The model is evaluated through comparison with available experimental data and empirical models obtained from the literature for compressed metal foams. The compressed RUC model predictions produce expected tendencies of geometrical parameters of metal foams under compression and the comparison with experimental data reveal satisfactory results.