A general correlation for mass transfer in isotropic and anisotropic solid foams

Many open-cell foams exhibit ellipsoidal rather than spherical cells. The extent of the anisotropy of the structure typically increases with decreasing cell density. In dimensionless transport correlations, an anisotropy factor has to be introduced in order to lend them general applicability. This paper reports on such a correlation for mass transfer which has been proven to be useful for ceramic and metallic foams with pore counts between 10 and 45 ppi and porosities between 75% and 95%. Based on this novel correlation it was also possible to apply successfully the Lévêque equation which enables the prediction of mass transfer coefficients from pressure drop data.