DEM SIMULATION OF PARTICLES FLUCTUATION IN A GAS-SOLID BUBBLING BED

摘要

The discrete element model of soft ball was applied to simulate the gas-solid flow in a bubbling fluidized bed.The influence of the restitution coefficient and elasticity coefficient of particles on the bubble shape in the dense phase of fluldized bed was investigated.The results showed that the elasticity coefficient had little influence on the macro behavior of the gas-solid flow, but they had great influence on the meso-scale particles fluctuation.A small elasticity coefficient would cause the deformation of particles agglomeration and particles eddy, and would lead to the deviation of studying on the mesoscopic scale of bubbling bed.The restitution coefficient played an important role on the gas-solid flow characteristics of bubbling beds.With the increase of restitution coefficient, the bed height increased, indicating the decrease of energy loss and particles temperature.