“…In the typical case of well-connected pores, diverse physical phenomena in porous media, such as fluid flow, heat and mass transfer, gas adsorption, and phase transformations, may be amenable to homogenized macroscopic descriptions [2], although the exact connection with microscopic details of the porous medium is not always clear. Remarkably, any continuum model implicitly assumes that the overall effects of the often nontrivial pore-space morphologies [3] can be encapsulated in a small number of parameters, e.g., porosity, φ, tortuosity, τ , intrinsic permeability, k s , effective thermal conductivity, k e , etc., and the state of any fluid phase can be described by a small number of distributed state variables, e.g., pressure, p, saturation, s, etc.. For certain simple physical processes, especially those involving a single fluid phase, simple continuum formulations generally work well, and a rigorous connection between the porescale and continuum-scale governing equations can be sought -examples include single-phase flow [4,5] and heat transfer [6,7] -although estimating the transport coefficients from microscopic features of the porous medium is still an open research problem [8,9,10,11,12].…”