Water retention in discrete element method

Abstract

We describe water movement and retention using the discrete element method in view of future modelling of partially saturated granular materials. By defining the water potential in terms of capillary bridges at low saturation, and in terms of pressure of entrapped air at high saturation, we investigate the hysteresis of water retention in granular materials during wetting and drainage. These phenomena are successfully underpinned by our model thanks to an equation that determines the local evolution of liquid-solid contact angles at the level of pores and grains.