Abstract
An experimental study was performed on phenomena related to the instability induced by a transverse electric field at an otherwise flat interface between a laminar film of a dielectric liquid and air which is either stagnant or forced to flow cocurrently with the liquid. The instability is characterized by two-dimensional ridges parallel to the flow direction when the liquid layer is thin enough, conical crests when the liquid layer becomes thicker, or cylindrical stems, each extending to the upper electrode surface, when the air layer becomes thinner. The instability-inception condition and the dynamic feature of destabilized interface are described.
