Synthetic jet actuator efficiency based on the reaction force measurement

Abstract

The efficiency of the devices is often a determinant of the technological advancement. The aspects of increasing the efficiency of the devices has been studied and improved over the years. The energetic efficiency of the synthetic jet actuators is often defined as the ratio of the kinetic power to the electric power feeding the actuators. In this paper, a new practical experimental procedure for evaluating a kinetic power based on the measurement of the time-mean reaction force was presented. The new procedure is independent from the actuator type, the number of actuators and orifices, as well as the shape of the orifices. The paper presents a comparison of the SJAs efficiency based on a spatially and temporally averaged synthetic jet momentum velocity and a time averaged reaction force measurements. The results of the efficiency in both methods are convergent. The paper presents the experimental investigation of the efficiency for single and double acting, single and multiple axisymmetric orifices synthetic jet actuators. It was noticed that the double acting synthetic jet actuator achieved 12% higher efficiency than the single acting SJA.