THE IMPACTS OF STANDARD WALL FUNCTION AND DRAG MODEL ON THE TURBULENT MODELLING OF GAS-PARTICLE FLOW IN A CIRCULATING FLUIDISED BED RISER

摘要

A transient turbulence model was applied to simulate the gas-particle system in a circulating fluidised bed riser. The /c-epsilon turbulent equations coupled with the fluctuating energy equation were used to simulate the gas-particle system in a riser. The simulation results were validated by the experimental data of a CFB system. A grid study was implemented to examine the impact of grid discretisation. A comparison between the conventional drag models and the EMMS model was also conducted. Other factors, like the restitution coefficient particle to particle, was also found to have a significant impact on the turbulence model.