Experimental technique based on delay phase angle and PIV measurements of a dual synthetic jets actuator

Abstract

There is a delay phase angle between the displacement signal and voltage signal of PZT-driven actuator. The higher the driving frequency, the larger delay phase angle of the PZT vibrator will be. Based on the delay phase angle of the PZT vibrator, a transfer-phase and sub-frequency (TPSF) technique was provided to capture the arbitrary phase of the dual synthetic jets, and a transfer-phase to equal (TPE) technique was provided to determine the phase of the dual synthetic jets. A PZT-driven dual synthetic jets actuator was measured based on the technique. The results demonstrate the TPSF and TPE techniques are effective. And a circle of the dual synthetic jets is divided into “left” stage and “right” stage. In the “left” stage, the dual synthetic jets flow-field is dominated by the left jet; and in the “right” stage, the dual synthetic jets flow-field is dominated by the right jet. In the near field downstream of the dual synthetic jets actuator, the two jets entrain fluid around them and interact with each other, and the flow-field is more complex and there is a phenomenon of “self-support” between the dual synthetic jets. In the far field downstream of the dual synthetic jets actuator, the two jets merge a single, more stable synthetic jet.