A new approach for determining the permeability of cellular metals

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.

Open-cell metal foam has enjoyed significant industrial and scientific interest as a viable multi-functional engineering material. Metal foam posses a number of advantageous properties. Several applications require fluid flow through the open pores of metal foam. A key flow property of metal foam is the permeability, which has been subject to research and debate for a long time. This paper presents a new approach for evaluating this critical transport property by considering the physics of energy dissipation, i.e., the viscous shear and form drag. The current work emphasizes the necessary initial step of clearly distinguishing between different flow regimes (Darcy and Forchheimer), prior to evaluating the permeability. This distinction is sometimes absent or overlooked in several previous studies. The new approach is used to determine two types of permeability for wind-tunnel steady-state unidirectional airflow through open-cell aluminum foam samples having different pore densities.