Experimental investigation of plate cooling by ionic wind from a needle electrode

We have investigated experimentally the cooling of a heated plate playing the role of a grounded electrode by a narrow intense ionic wind jet produced by a needle electrode and directed along the normal at the plate center. For a fixed average temperature of the heater, we have obtained the dependence of the heat power removed with the wind on the electric power spent for sustaining the corona discharge for various interelectrode distances and voltages. It is shown that a small ionic wind jet can effectively cool a massive plate, removing up to 23 W of heat power for a spent electric power of up to 0.7 W. We have also studied experimentally the structure of ionic wind in the electrode system considered. A laser anemometry setup was used for visualizing the flow and for obtaining velocity distributions. The velocities in the central jet of ionic wind reached 8 – 9 m/s. The jet was narrower and faster for the positive polarity of the corona discharge. However, the efficiency of cooling for positive and negative polarities was approximately the same.