Experimental investigation on the performance of a novel dual synthetic jet actuator-based atomization device

Abstract

A synthetic jet actuator is a zero net mass flux device. In order to improve the compactness of spray cooling system, a novel dual synthetic jet actuator-based atomization device (DSJAA) is proposed and designed. In this atomization system, water is atomized by the oscillating dual synthetic jets instead of high-pressure air source. Moreover, no extra power for supplying water is needed. The effects of driving voltage, driving frequency, fluid volumetric flow rate and spray height are investigated on atomization rate, water droplet size, surface temperature and heat flux. The maximum atomization rate is 3.4 L/h at driving frequency of 700 Hz and driving voltage of 210 V. The dimensionless correlations between the physical properties of dual synthetic jet and the size of water droplet are presented, which provides guideline for the design of a dual synthetic jet actuator-based fluid atomizer. The experimental results show that when the resonance frequency of piezoelectric diaphragm is equal to half the Helmholtz frequency of DSJAA, the atomization performance is the best by setting driving frequency to resonance frequency. The best spray height is equal to the fluid stroke length of DSJAA. The cooling capability is mainly influenced by the Reynolds number of dual synthetic jet and volumetric flow rate of water. A correlation for DSJAA cooling is established. A maximum heat flux of the novel spray cooling method reaches as high as 59 W/cm2 in the experiments.