Pressure Drop in and Equivalent Particle Diameter for Aluminum Foam

Patel, Pragnesh, and Nihad Dukhan

Metal foam is a relatively new class of porous media. Its internal architecture is significantly different than traditional porous media. This aspect provides a set of challenges for researchers trying to understand the fluid flow in this material. This paper proposes that despite the geometrical differences between the metal foam and more traditional porous media, the Ergun correlation is a good fit for the pressure drop data as a function of the Darcian velocity. This is especially true for the porosity dependence of the linear pressure drop. The paper also investigates appropriate effective particle diameters derived from some of the parameters of the foam, and considering the physics of the energy dissipation that contributes to the pressure drop. The above is supported by wind-tunnel steady-state unidirectional pressure-drop measurements for airflow through several compressed and uncompressed isotropic open-cell aluminum foam samples, having different porosities and pore densities. For each foam, the particle diameters are correlated with the surface area density.