Experimental Study on Characteristics of Plasma Synthetic Jet Actuators with Different Insulating Materials

Plasma synthetic jet actuator (PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity. In this article, Nylon and Teflon were selected as the insulation materials of synthetic jet actuators to make use of the ionization ablation properties of thermoplastic materials to improve the actuator performance. The performance differences between these actuators and traditional ceramic synthetic jet actuator are obtained. Based on electrical measurement and high-speed schlieren image system, the electrical characteristics and jet performance of the three kinds of actuators at different air pressures are studied. The discharge voltage, current waveform, discharge efficiency, and discharge energy of the three kinds of actuators were almost the same under different pressures. However, Nylon and Teflon materials will be ablated after ionization, resulting in higher jet velocity and longer jet duration time than traditional actuator of ceramic. The ablation of Teflon was most serious. The Teflon actuator had the maximum jet velocity up to 447.51 m/s at 20-kPa pressure. Based on the schlieren image processing method, the affected area of the actuator was calculated. It was found that the maximum affected area of the Teflon actuator was 144.84% larger than that of the ceramic actuator at 100 kPa. The synthetic jet actuator of Teflon had larger affected area and higher jet velocity than other actuators, so it has great application value in high-speed flow field control.