Hydrodynamic interactions between electrically charged grains in suspensions

In suspensions with charged particles, electrostatic forces and hydrodviiamic interactions are both important to describe the system. We study different models of hydrodynamic interaction for monopolarly charged particles in a nonpolar liquid. In this case, there is no screening of the Coulomb repulsion, so the repulsion between all pairs must be taken into account. For some selected systems we examine different models of hydrodynamic interaction, and we show that anomalies and unphysical behaviour in many cases result. We propose a way to model the interaction which does not suffer from these problems.