Lattice-Boltzmann Simulations of Transport Phenomena and Structuring in Suspensions

We simulate particles suspended in a fluid by means of the lattice-Boltzmann method and its extension to particle suspensions as introduced by Ladd et al. in order to study transport phenomena and structuring effects of particles in the vicinity of sheared rigid walls. We find that a particle free region arises near walls, which has a width depending on the shear rate and the particle concentration. The wall causes the formation of parallel particle layers at low concentrations, where the number of particles per layer decreases with increasing distance to the wall. These findings are in good agreement with a phenomenological theory of Muckenfuss and Buggisch. We also study the velocity distributions of suspended particles which turn out to be non-Gaussian, but exponential