Estimates of equivalent aperture for non-Newtonian flow in a rough-walled fracture

In this work, theoretical estimates of equivalent apertures for creeping flow of a purely viscous power-law fluids in a rough-walled fracture have been obtained, generalizing past results for a Newtonian fluid. As expected, the equivalent aperture is lower than the mean in flow perpendicular to the profile, and larger in the parallel flow configuration. In both cases, the equivalent aperture is larger for pseudoplastic fluids than for dilatant ones. It was demonstrated that tortuosity effects decrease equivalent aperture below the mean; the reduction effect is more evident for pseudoplastic fluids.