Reproducing micro X-ray computed tomography (microXCT) observations of air–water distribution in porous media using revised pore-morphology method

Abstract

This study presents a novel and simple morphology approach to generate two-dimensional air–water distribution in porous media considering Or and Tuller’s cavitation mechanism (published in 2002). The connectedness condition for the nonwetting phase is replaced by the Laplace equation. An algorithm is developed to detect the ruptured water spaces that are incorrectly formed in the throat by the morphology approach, but cannot exist in a real thermodynamic equilibrium system. The distributions of soil moisture, water retention curve, and air–liquid interface area at different saturations predicted by this method are in a good quantitative agreement with the experimental observations on glass beads and Ottawa sand from micro X-raycomputed tomography (microXCT). Compared to Lu et al.’s Monte Carlo lattice-gas approach (published in 2010), another computational method to generate the soil moisture distribution, the proposed approach provides better results with significantly less computational power.