Large Eddy Simulation of particle-laden turbulent channel flows with isotropic or non-isotropic wall roughness

Abstract

In particle-laden flows, particles rebound from rough wall can influence significantly properties of particle and fluid phase which can be important in number of industry processes. 2D stochastic procedures for such a rebound have been developed for representing the effect of wall roughness although such mechanism is generally 3D due to the particle incident velocity and roughness geometry. Therefore we have developed a general approach allowing to represent the 3D particle bouncing on isotropic or non-isotropic rough wall. Thus effect of the isotropic and non-isotropic roughness is evaluated using DPS/LES in horizontal channel flow. Inter-particle collisions are calculated using soft sphere model. Different LES subgrid models of pure fluid flow are examined and influence of subgrid turbulent fluid velocity on particle statistics is evaluated. Detailed information regarding particle velocity statistics are discussed with respect to wall roughness characteristics.