DEM-CFD simulation of fluidization characteristics for group geldart's a particles under couple's boundary condition

The simulation study of gas-fluidization characteristics for Group's A particles with couple s boundary condition was carried out by a method combining discrete element method and computational fluid dynamics(CFD-DEM). The characteristics of fluidization of this class particles was analyzed under the different velocities with the bed bottom s superficial velocity determined from the velocity field and not from a uniform value. The interaction between the flow and particle motions and their influence to the minimal fluidization velocity and minimal bubble velocity were analyzed. It was found that bed stability would be worse in couple s condition compared with the uniform value and the velocity distribution in the bed bottom was no uniform and the bubbles happened earlier in some place where fluid channeling formed and dead zones come into being in other place.