Simulation of solid-fluid interaction in granular flow of irregularly shaped particles via coupled LBM-DEM method

ABSTRACT: Simulating granular flow in geotechnical engineering is mostly associated with adopting a coupling method to simulate the interaction of solid grains and seeping fluid, such as using computation fluid dynamics to couple with the discrete element method. While this approach has enhanced our knowledge about the underlying mechanisms that trigger geohazards like landslides and internal erosion, most studies simplified soil particles as spheres and the morphological impact of particle’s shape is neglected. In this study, the lattice Boltzmann method (LBM) and the discrete element modeling (DEM) are coupled to simulate the interaction between irregular soil grains and fluid by using two open-source codes. For this purpose, the irregular shaped particles are represented by multi-sphere clumps in DEM, and LBM is used to account for the fluid part interaction at meso-scale. The accuracy of the coupled method is demonstrated by simulating several benchmark cases and comparing them with the results from literature. The coupled LBM-DEM method is then used to simulate the collapse and transport of submerged granular particles to demonstrate the influence of grain morphology in the solid-fluid interaction.