SUB-DARCY-SCALE MODELING OF NON-UNIFORM FLOW THROUGH POROUS MEDIA WITH MIXED WETTABILITIES

Abstract

A physically-based conceptual model is developed using spatially distributed sub-Darcy-scale
clusters in a regular grid to reproduce both the hydraulic properties and the non-uniform wetting and drainage
fronts through porous media mixed with hydrophilic and hydrophobic grains. In the model, cellular
automaton-like algorithm is employed to route water- and air-intrusion paths through the mixed porous media.
Water retention characteristics, which are ones of the macroscopic properties of porous media, are estimated
by accumulating a certain numbers of clusters after reaching equilibrium states in a wetting or drainage
process. In the experimental part of this study, normal (hydrophilic) and artificially hydrophobized glass
spheres, whose diameter is about 0.2 mm, are used as materials, and hydraulic properties of homogeneously
mixed glass spheres with various rates are measured. The measured data are compared to model estimation,
and the availability of the model is shown.