Electroconvective flow induced by dielectric barrier injection in silicone oil

Abstract

It has been demonstrated that dielectric barrier actuators can be used to induce electrohydrodynamics flows in air as well as in gas. These actuators are often called surface non-thermal plasma actuators in gas applications. Plasma actuators have proved their efficiency for aerodynamics flow control in air. However dielectric barrier devices don't generate plasma in liquids. Electroconvective flows are induced by charge injection at the surface electrode tip. These dielectric barrier injectors (DBI) are particularly well adapted for wall jet production vortex, shedding, and mixing layer applications in dielectric liquids. Dielectric barrier actuators have proved their efficiency on various dielectric liquids. In this study, a dielectric barrier device is tested on silicon oil. Instead of the typical wall jet, a reverse flow is observed in specific configurations. Particle Image Velocimetry and Shlieren measurements are achieved to characterize the unusual electroconvective flow.