Abstract: | The representation of the permeability coefficient tensor for capillary models of porous media displaying isotropic and anisotropic flow properties is considered. The representation proposed is compared with the Kozeny-Carman formula. It is shown that in general, as distinct from the widely accepted representation of the Carman constant in the form of a product of the form factor and tortuosity, this constant is equal to a combination of three coefficients, namely the form factor, the tortuosity, and the structure coefficient. The presence of the latter is due to the fact that in periodic capillary models the porosity is not equal to the surface porosity. It is shown that the Carman constant, the form factor, and the structure coefficient are not universal and their intervals of variation are calculated. The results obtained make it possible to explain and interpret numerous experimental data on the determination of the Carman constant in various porous media.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 96–104, July–August, 1996. |