Experimental Study on Impingement Cooling Characteristics of Synthetic Jet Flux Activated by Piezoelectricity

Hot-wire anemoscope was used to measure the velocity and the turbulence intensity of a synthetic jet activated by piezoelectric actuator with a two-dimensional slot nozzle.The influences of the various voltages and frequencies imparting to the synthetic jet actuator were investigated and the best actuating parameters were obtained.The temperature distributions and convective heat transfer coefficients on the target surface cooled by synthetic jet were measured by an infrared camera.The results show that:(1) when the jet-to-surface spacing ratio is less than 20,the synthetic jet is in the formation process and the cooling effect is worse;(2) when the jet-to-surface spacing ratio is greater than 20,the synthetic jet is steady and fully developed,the cooling effect is better;(3) when the distance is too far away from the nozzle,the velocity of the synthetic jet decreases,and the heat transfer coefficient reached the highest when the jet-to-surface spacing ratio is 80.