Experimental study on EHD heat transfer enhancement with a wire electrode between two divergent fins

Abstract

In this work, electrohydrodynamic (EHD) technology is utilized to enhance the heat transfer from the heat sink featuring two symmetrical divergent fins. With keeping the heat sink grounded, the tungsten wire placed between the fins is supplied with a high voltage to produce corona wind. The impingement velocity of the corona wind is controlled by the voltage and wire position. Increasing voltage can improve the heat transfer regardless of the wire position. At higher voltage, there exists an optimal wire position for maximum heat transfer. By optimizing the position, the average convection heat transfer coefficient can be increased to over 26 W m−2 K−1, which is 3.5 times that in natural convection. The ratio of convection heat transfer rate to EHD power consumption, that is the coefficient of performance (COP), is analyzed to optimize the energy efficiency of the EHD device. This study shows that it is not recommended to raise the voltage to be much higher than the corona onset value. The highest COP reaches almost 100.