A <scp>CFD‐DEM</scp> study of the solid‐like and fluid‐like states in the homogeneous fluidization regime of Geldart A particles

Abstract

Abstract The mechanisms underlying homogeneous fluidization of Geldart A particles have long been debated. Recent experiments shed fresh insights that both a solid‐like and a fluid‐like state exist. Herein, 3D computational fluid dynamics‐discrete element method simulations with the incorporation of interparticle van der Waals forces were performed for five typical Geldart A particles to investigate the bed structure in the homogeneous fluidization regime. Simulation results reproduce the existence of the solid‐like and fluid‐like states, showing that in the solid‐like state, particles have enduring and strong interparticle van der Waals forces that stabilize the bed to keep the bed stationary; while in the fluid‐like state, the interparticle van der Waals forces are dominated by the drag force, and particles show global circulation. Both interparticle van der Waals forces and friction are found to be necessary for the existence of the solid‐like state, and increasing the former has an effect to widen the solid‐like state.