稠密气固流动中颗粒聚集现象的数值模拟

Numerical Simulation of Cluster Formation in Dense Gas-Solid Flow

基于确定性轨道和真实碰撞,对二维稠密气固两相流动进行了数值模拟,真实展现了颗粒聚集现象从无到有的发展过程.在此基础上,对颗粒聚集现象影响因素的作用规律进行了研究.结果表明,颗粒间的相互碰撞是造成颗粒聚集的重要原因,即使在初始颗粒体积分数低至0.24%的情况下,仍然有显著的颗粒碰撞发生和聚集出现.颗粒弹性恢复系数越小、颗粒初始体积分数越大,则颗粒聚集现象越明显.这与已有的一些实验和数值计算结果是一致的.

Based on the deterministic trajectory and real inter-particle collison, numerical simulation of two-dimensional dense gas-solid flow was carried out for visualizing the process of cluster formation. The effects of inter-particle collision, original particle volume fraction and particle restitution coefficient on the cluster formation were investigated. The inter-particle collision is a definitive factor for cluster formation process. The inter-particle collision and the clusters are obviously observed even when the original particle volume fraction is as small as 0.24%. Reduction of particle restitution coefficient and increase of original particle volume fraction are favorable for cluster formation. The results are consistent with some experiments and previous numerical simulations.