Abstract
Large Eddy Simulation of downward fully developed particle-laden turbulent channel flows were performed with considering inter-particle collisions and fluid sub-grid scale components at Reynolds number 180 and 644 respectively. The effects of Stokes numbers, turbulence sub-grid scale components and inter-particle collisions on the distributions of solid particles were discussed. It was verified that, regardless of the Reynolds number of fluid flows, the maximum departure from randomness is when the ratio of the particle's aerodynamic response time to the Kolmogorov time scale of flow was approximately one. In addition, the simulation results showed that the degrees of particle preferential concentration are selectively associated with the sub-grid scale components of fluid turbulence because preferred particles were affected by preferred scale of the eddy structure around.
