Reynolds number effect on particle-laden channel flows

The effect of Reynolds number on particle velocity statistics and preferential concentration in a channel flow are studied using large eddy simulation and a Lagrangian particle tracking technique. Three different particle Stokes numbers (St = 1, 5, 25), a measure of particle inertia, are investigated for four different shear Reynolds numbers, Reτ = 150, 300, 590 and 2000, corresponding to transitional, low, moderate and high levels of turbulence. It is found that for all Reynolds numbers studied an increase of the particle Stokes number increases the preferential concentration of the particles in the near-wall region, while for a fixed Stokes number, increasing the turbulence of the fluid reduces the extent to which the particles accumulate at the wall.