Direct simulation of electrical and hydraulic tortuosity in porous solids

Abstract

We directly evaluate the fluid‐flow and electrical conductivity of model three dimensional random porous medium at a microscopic level. This allows a direct test of the popular assumption that fluid‐flow and electrical current follow equivalent flow paths in porous solids. Visualisation of the fluid‐flow and electric‐current streamlines within identical porous samples show this assumption is incorrect. The tortuosity factors, characterising the geometry of the flow paths associated with fluid‐flow and electrical current transport, are directly evaluated. Fluid‐flow tortuosity is systematically larger than the electrical tortuosity, and can differ by as much as an order of magnitude at lower porosities. Show more