Simulation of Electrohydrodynamic Jet Flow in Dielectric Fluids

Abstract

When a dielectric fluid is exposed to a high electric field (>1 kVmm -1 ), electric forces are generated due to the nonuniformity of electric conductivity and dielectric constant. The electric body forces often produce complex and macroscopic flow such as convection, turbulent and chaotic flow. The secondary flow induced in high electric fields is well known as electrohydrodynamic (EHD) effects. According to previous EHD experiments and numerical simulation in DC fields, the velocity of flow has been reported to be of the order of 10 -2 ms -1 in electric fields of several kVmm -1 . However, on the application of high DC electric fields to some dielectric oils, a fluid jet with a velocity of about 1 ms -1 can be created from the positive electrode as a bulk flow. In this study, the numerical simulation of EHD jet is carried out from the engineering aspects. The high speed jet flow is theoretically reproduced, and the obtained flow patterns are compared with the experimental results under the conditions of simple electrode allocations.