Numerical study of water-air distribution in unsaturated soil by using lattice Boltzmann method

Identification of water-air distribution at meso-scale in unsaturated soil is of great significance in the field of soil studies. In order to better understand the water-air distribution in soil pore, a meso-scale numerical model was developed: (1) a stochastic generation method was developed for the generation of mesoscopic soil structure, (2) the lattice Boltzmann method was selected for the numerical solutions of multiphase flow partial differential equation (PDE) in soil pore, (3) the water-air interface was tracked by using Shan-Chen model. The generation of soil structure and the solution of governing equations were completed by Open Source Lattice Boltzmann Code (OpenLB). The simulated water-air distribution shapes were almost the same with those reported in literature, indicating that the model developed in this study can be well used to evolve the water-air interface formation. Water-air distributions in soil pore at different porosities, wettabilities and saturations were detailed. (C) 2019 Elsevier Ltd. All rights reserved.