Stabilization of a suspension of sedimenting rods by induced-charge electrophoresis

We use numerical simulations to investigate the dynamics in suspensions of ideally polarizable rods sedimenting under gravity in a vertical electric field. While such suspensions are unstable to concentration fluctuations when no field is applied, we show that the induced-charge electrophoresis that results from the application of the field provides control over the concentration instability by causing particle alignment in the field direction. A phase diagram is obtained for the occurrence of the instability in terms of field strength and volume fraction. In stable suspensions velocity hindrance is shown to occur, and results for the hindered settling function are presented.