On Various Flow Regimes in Open-Cell Metal Foam
Nihad Dukhan and Mohamed Ali
Flow regimes are important for understanding the nature of fluid flow and pressure drop in metal foam. While they are well-studied and agreed upon for open pipe flow and, to an extent, for traditional porous media, this is not the case for flow in open cell metal foam. This paper presents various flow regimes in two types of open-cell metal foam. For each flow regime, certain values for the permeability and form drag coefficient are exhibited by the foam. The traditional Reynolds number for pipe flow is favored in marking transition from laminar to turbulent flows. Values of the permeability and form drag coefficient are obtained for the different flow regimes, by first distinguishing flow regimes. The Forchheimer equation is shown to represent the pressure drop in both the transitional and turbulent flow regimes. A discussion about two kinds of transition and their physics is provided.
Keywords: Metal foam; flow regimes; pressure drop; permeability; turbulence.