Relevance of capillary interfaces simulation with the Shan-Chen multiphase LB model

This paper presents a numerical study of capillary interfaces using the Single Component Multi-Phase Shan-Chen model, which is based on the lattice Boltzmann method. Despite the simplicity of the model, it has been shown to be effective and the present study aims to test its ability to correctly reproduce the physics of multiphase systems. To this end, several benchmark simulations were carried out in the configurations of a drop on a flat wall and then on a spherical surface to characterize the wetting behavior and relate explicitly the contact angle to model parameters. In addition, the capillary forces induced by a liquid bridge between two spherical particles were numerically calculated. We show that the results obtained are in agreement with experimental and theoretical results from the literature. The model is thus accurate in addressing the wetting behavior and capillary interfaces in unsaturated granular soils despite the fact that surface tension and contact angles are not explicit parameters of the model. To this respect, explicit relationships with Shan-Chen parameters are provided.