GENERALIZATION OF DARCY LAW FOR NONUNIFORM FLOWS

A generalized Darcy's law for nonuniform flows in which the pressure gradient depends on the velocity and its derivatives is adopted. The permeability coefficient, as well as a new coefficient, is investigated with the aid of the averaged dissipation equation. The additional coefficient appearing in the generalized law is estimated with the aid of a cell model, and the generalized law is employed in order to solve a few problems (Couette flow past a porous boundary, refraction at the boundary between two porous samples, and flow around a thin partition). Deviations from Darcy's law are found to be confined to thin layers near the medium boundaries. Copyright 1979 by the American Geophysical Union.