LARGE-EDDY SIMULATION OF A PARTICLE- LADEN TURBULENT CHANNEL FLOW

Abstract Large-eddy simulations of a vertical turbulent channel ow with 420,000 solid particles are performed in order to get insight into fundamental aspects of a riser ow. The question is addressed whether collisions between particles are impor-tant for the ow statistics. The turbulent channel ow corresponds to a particle volume fraction of 0.013 and a mass load ratio of 18, values that are relatively high compared to recent literature on large-eddy simulation of two-phase ows. In order to simulate this ow, we present a formulation of the equations for com-pressible ow in a porous medium including particle forces. These equations are solved with LES using a Taylor approximation of the dynamic subgrid-model. The results show that due to particle-uid interactions the boundary layer be-comes thinner, leading to a higher skin-friction coefcient. Important effects of the particle collisions are also observed, on the mean uid prole, but even more on particle properties. The collisions cause a less uniform particle concentration and considerably atten the mean solids velocity prole