Coupled CFD-DEM Simulations: A Review of Applications and Modeling Limitations

This paper reviews fluid-particle interactions and implementation in coupled computational fluid dynamics (CFD) and discrete element modeling (DEM). Soil particles interact with water flow in various geotechnical engineering applications such as seepage and groundwater flow. Understanding these interactions is critical for the design of effective systems to mitigate potential instabilities and manage surface runoff. Coupled CFD and DEM simulations have been used widely to account for the presence of water in soils. In this study, we review the applications of coupled CFD-DEM in geotechnical engineering. Further, we present a coupled CFD-DEM numerical model, developed using both COMSOL Multiphysics and PFC3D. We first validated our model by comparing the model results to the physical tests on settling velocity of a gravel particle in media with different viscosity. Then, we highlighted some challenges and limitations in adopting coupled CFD-DEM in geotechnical research. The developed CFD-DEM model will be used in future studies to model both the surface and internal erosion of various construction soils.