Enhancement of forced convection heat transfer on LED by ionic wind

Abstract

The main purpose of this study is to investigate the heat transfer enhancement provided by ionic wind on LED. Ionic wind is applied onto a bulk flow in order to distort the boundary layer in an effort to increase the cooling effect on the LED. The ionic wind generator used in this case involved a stainless steel needle acting as emitter electrode while a copper tape is used as collector electrode. Both electrodes are placed in parallel to each other. An axial fan is placed at the inlet of a flow channel to provide the bulk flow. A maximum heat transfer enhancement of 38 % by ionic wind is recorded at applied voltage of 16.3 kV as compared to the case without ionic wind. The heat transfer enhancement is found to be independent of the bulk flow velocities and the ratio of heat transfer coefficient over total consumption is found to be at 63.75 W/m2K per unit power at the maximum heat transfer enhancement.