Sedimentation of non-Brownian suspensions

We describe the sedimentation of a non-Brownian suspension of hard spheres by Stokesian dynamics simulations. Attention is focused on the mean settling velocity and the structure of particles distribution as the suspension attains a non-equilibrium steady sedimentation state. Many-body hydrodynamic interactions between particles are evaluated using the precise multipole method, encoded in the new FAST-HYDROMULTIPOLE program. With the complete neglect of Brownian motion, the sedimentation velocity and the particles configurational distribution in the steady state differ measurably from their equilibrium counterparts. Simulations reproduce short-range particle correlations in good agreement with the statistical description of sedimentation formulated by Cichocki and Sadlej [Europhys. Lett. 72, 936 (2005)].