中国化学工程学报（英文版）
中國化學工程學報（英文版）
중국화학공정학보（영문판）
CHINESE JOURNAL OF CHEMICAL ENGINEERING
2006年
2期
141-148
,共8页
gas-solid flows%particle cluster%Lagrangian approach%large eddy simulation
Two-dimensional unsteady cocurrent upward gas-solid flows in the vertical channel are simulated and the mechanisms of particles accumulation are analyzed according to the simulation results. The gaseous turbulent flow is simulated using the large eddy simulation (LES) method and the solid phase is treated using the Lagrangian approach, and the motion of the gas and particles are coupled. The formation of clusters and the accumulation of particles near the wall in dense gas-solid flows are demonstrated even if the particle-particle collisions were ignored.It is found that a cluster grows up by capturing the particles in the dilute phase due to its lower vertical velocity. By this way the small size clusters can evolve to large-scale clusters. Due to the interaction of gas and particles, the large-scale vortices appear in the channel and the boundary layer separates from the wall, which results in very high particle concentration in the near wall region and a very large-scale cluster formed near the separation point.
