Improving thrust by pulse induced breakdown enhancement in AC surface dielectric barrier discharge actuators for airflow control
The characteristics of a plate to plate AC surface dielectric barrier discharge (SDBD) actuator using the pulse induced breakdown enhancing method are experimentally investigated. The encapsulated electrode is supplied with a sine high AC voltage, while the exposed electrode is feed by a synchronized pulse voltage. Based on the thrust force and power consumption measurements, a parametric study was performed using a positive pulse applied at the trough phase of the AC cycles in which the thrust force was observed to increase by about 100% to 300% and the efficiency up to about 100% compared with the AC only supply conditions for different AC voltages within the tested range. The pulse induced breakdown effect was analyzed from the electrical and light emission waveforms to reveal the underlying mechanism. The surface potential due to the charge deposition effect was also measured using a specially designed corona like discharge potential probe. It is shown that the pulse induced breakdown was able to cause a temporarily intensified local electric field to enhance the glow like discharge and meanwhile increase the time average surface potential in the region further downstream. The improvement in the force by the enhancement in the pulse induced breakdown was mainly due to enhancements in the glow like discharge and the surface potential increment, with the latter being more important when the AC voltage is higher.