Heat Transfer Characteristics of a Heat Sink in Presence of a Synthetic Jet

Abstract

The heat transfer characteristics of a typical heat sink used in conjunction with an impinging synthetic jet are experimentally investigated in this paper. The experiments are conducted for several excitation frequencies, different shapes of the synthetic jet orifice having the same hydraulic diameter, and several axial distances from the tip of heat sink fins to the orifice plate. In addition, experiments with a fan placed on top of the heat sink are conducted at different input powers to the fan and for different axial distances. The performance of the heat sink in terms of the overall thermal resistance is documented. The heat transfer coefficient with the heat sink is found to be approximately four times greater with the impinging synthetic jet with the impinging synthetic jet than that for the bare surface. Different shapes of the orifice with identical hydraulic diameter have negligible effect on the thermal performance of the heat sink. The synthetic jet is deduced to perform better than a continuous jet but worse than a commercial fan. These results of an impinging synthetic jet on a heat sink have not been reported earlier and are expected to have practical utility.