A coupled distributed Lagrange multiplier (DLM) and discrete element method (DEM) approach to simulate particulate flow with collisions
Govind Sharma, Nishant Nangia, Amneet Pal Singh Bhalla, Bahni Ray
Abstract
In this paper, a coupled DLM-DEM numerical approach is proposed to enable particle-particle and particle-wall interactions within the open-source IBAMR (Immersed Boundary Adaptive Mesh Refinement) framework. A soft-sphere DEM collision model is adopted and compared against the particle-particle repulsion force model suggested in the literature. It is demonstrated that the former collision model remains effective at both low and high particle-fluid density ratios, whereas the latter model can lead to unphysical particle-particle interaction dynamics at high density ratios. Moreover, the soft-sphere DEM collision model is based on physical material properties, which is in contrast to an artificial parameter-based repulsion force model. The proposed DLM-DEM approach is validated by simulating the particle-particle collision in drafting, kissing, and tumbling (DKT) phenomenon, and particle-wall collision at various Stokes numbers. Using this approach, we also simulate the interactions between a single colliding particle and a particle cluster and analyze the particles' motion and distribution. Additionally, sedimentation of polygon-shaped particles is also considered to demonstrate the versatility of the proposed approach.