Theoretical study of EHD instability in a system of conducting and insulating liquids at unipolar injection

摘要

Two layers of insulating and conducting viscous liquids confined between two plane parallel electrodes and subjected to a unipolar ion injection are considered. The linear electrohydrodynamic instability in this system is studied theoretically. The critical Rayleigh numbers are determined for a wide range of parameters: weak and strong injections, by rigid electrode or through the liquid-liquid interface, for different ratios of the liquid viscosities and liquid layer thicknesses. The viscous shear forces acting at the liquid interface have a destabilizing effect in comparison with the case of a single layer between rigid electrodes or a rigid electrode and the free surface.