Simulating the fluid-solid interaction of irregularly shaped particles using the LBM-DEM coupling method

In this paper, the lattice Boltzmann method (LBM) and the discrete element method (DEM) are coupled to simulate the interaction between the fluid phase and irregularly shaped solid particles. For this purpose, the geometry of realistic particle shapes is represented as clumps of overlapping spheres and then simulated through a multi-sphere model in DEM and coupled with LBM using two open-access codes, LIGGGHTS and Palabos. The accuracy of the coupling method with clumps is demonstrated by simulating several benchmark cases and comparing them with the results from the literature. The coupled LBM-DEM method is then used to simulate the collapse and transport of submerged granular particles with spherical shape and irregular shape, respectively, to highlight the influence of grain morphology in the solid-fluid interaction. Compared with previous LBM-DEM coupling for highly idealized non-spherical shapes, the research provides a more realistic computational framework to capture the complex irregular particle shapes of geomaterials with clumps/multi-spheres, which is useful for studying the underlying effect of particle shape on geotechnical issues such as internal erosions.