No abstract

h i g h l i g h t s An upscaling methodology is proposed to characterize fluid flow in porous media with rough surfaces. The no-slip condition on the rough surface is replaced with a tensorial slip condition on a fictive smooth surface. The permeability decreases significantly, even for small amplitudes of the roughness. The pressure drop is accurately predicted for structured packings used in separation processes. Different regimes are identified in the transition from creeping flow to the onset of unsteady inertial flow.