Numerical analysis of the effect of an EHD actuator on the flow past a square cylinder

In this paper we demonstrate how it is possible to control the flow of a dielectric liquid past a square cylinder with a simple actuator based on three electrodes ideally placed on its surface. Two-dimensional numerical simulations coupling the flow and the EHD equations have been undertaken and the vortex shedding occurring when the Reynolds number is high enough has been controlled. Indeed, the secondary flow induced by the electric charge injected from the two emitters electrodes interacts with the primary flow and suppresses the vortex shedding and wipe out the Karman vortex street supposed to evolve in the wake for a short while. Later, the flow recovers its periodic structure but this time the frequency and amplitude of the vortex shedding is clearly decreased. Flow patterns are displayed showing this effect.