Abstract
The influence of an applied electric field upon the linear stability of a shear layer between two dielectric fluids of exponentially varying densities streaming at constant velocities is investigated. The electric field has a constant value over the fluid system, and is either parallel to the direction of streaming or normal to it. Viscosity is neglected, but the surface tension at the interface is taken into account. Limiting cases such as the Rayleigh-Taylor instability, and the non-influence of buoyancy upon inertia are investigated, as well as long and short wave numbers limits. Stability conditions are obtained for each case separately. It is found that when the effect of fluid heterogeneity on inertia is absent, there is a striking similarity between the effects of density variation and of rotation on the onset of instability.