Porous medium
= Porous medium
A porous medium is a solid framework containing connected voids in which a <fluid> can reside and flow. Its <porosity> is the void fraction; its <permeability of a porous medium> measures the ease of pressure-driven flow through the connected pores. The averaged <Darcy flux> is measured per total cross-sectional area, whereas the pore velocity is that flux divided by porosity. Not every material with voids has connected permeable pores.