Numerical Calculation of Electrical Conduction and EHD Motion Induced in Mineral Oil after Reversal of Electrode Polarity

Abstract

I have studied the relationship between electrical conduction and the EHD motion induced in mineral oil, between metal electrodes when their polarities are reversed. This paper describes the results of a three-dimensional numerical calculation on the relationship between electrical conduction and EHD motion. The equations used in the calculation are Euler's equation of continuity, the Navier-Stokes equation, Poisson's equation, and the equation of charge continuity. Primarily, the time dependence of the current waveform, the distribution of charge density, and flow velocity are calculated. The main results are as follows: (1) The EHD motion increases the current, inducing a peak in the current waveform. (2) The coulomb force in the vicinity of the electrode/oil interfaces after the reversal of the electrode polarity satisfies the condition for inducing EHD motion. (3) The distribution of space charge density and the flow velocity between electrodes are visualized using a three-dimensional diagram of contour surfaces and the three-dimensional vector diagram.