The effect of rotation on electrohydrodynamic instability

Abstract

The effect of uniform rotation on the onset of convective instability in a dielectric fluid confined between two horizontal planes under the simultaneous action of a vertical ac electric field and a vertical temperature gradient is considered. Applying linear perturbation theory and approximations analogous to the usual Boussinesq approximations, an equation of tenth order is derived. Under somewhat artificial boundary conditions, this equation is solved exactly and the eigenvalue equation is obtained. It is shown that (1) the principle of the exchange of stabilities is valid for most dielectric fluids; (2) the Coriolis force has an inhibiting effect on the onset of instability even if the electrical effect is taken into account; (3) as the speed of rotation increases the coupling between the two agencies causing instability (electrical force and buoyancy) becomes tighter.