Numerical investigation of the electro-thermo-convection of dielectric liquid in a square cavity with vertical walls composed of alternately arranged electrodes

Abstract Research on the improvement of the heat transfer performance by forming a voltage difference in the dielectric fluid has been actively conducted in the recent years. This study investigates the electro-thermo-convective flow in a two-dimensional (2D) square cavity composed of cold right and hot left walls. We introduce herein the results of the heat transfer enhancement when positive and grounded electrodes are alternately arranged on each vertical wall instead of installing the same kind of electrode (positive or grounded electrode) on the entire surface of a vertical wall. The case of alternately arranged electrodes demonstrates that the heat transfer coefficient increases more than twice compared to that of the single kind of electrode. The heat transfer enhancement by the electric field is maximized in the low Rayleigh condition. In the Ra = 2000 and T = 1000 condition, the alternately placed electrodes accomplished a 10 times higher heat transfer coefficient when compared to the pure natural convection. The heat transfer results of using a silicon oil have been summarized for the Rayleigh number range of 2000 to 106 and electrical Rayleigh number of 0 to 1000.