Sharp and Rounded Cutouts in a Chevron Orifice and Them Impact on the Acoustic and Flow Parameters of Synthetic Jet

Abstract

The application of a synthetic jet actuator in workplaces entails the necessity of noise reduction, which they generate. One of the methods to achieve this is the use of the chevron orifice or nozzle. Therefore, the impact of different numbers of chevrons and rounding of cutouts in the orifice on the actuator efficiency and the sound pressure level was tested. The chevron orifices were compared to the circular orifice. The time-mean reaction force method was used to measured efficiency and flow parameters, and the noise was measured according to the ISO 3746:2010. The rounded cutouts had an advantageous impact on the actuator efficiency at the power P >1 W, while the efficiency of the actuator with classic chevron orifice was smaller than with circular orifice. The noise generated by the actuator with the chevron orifice was smaller from 0.6 to 1.6 dB than by the actuator with the circular orifice, at the number of chevrons equal to 7 or more. The rounding of cutouts in the chevron orifice can advantageously impact the parameters of synthetic jet actuators.