Effect of electrode geometry on the flow structure induced by plasma actuators

Abstract

Pulsed Surface Arc Discharge (PSAD) is one of the essential techniques in flow control. In this paper, the effects of electrode configuration on the heat transfer characteristics of PSAD and the disturbance characteristics of PSAD on the flow field were investigated by thermal imaging and high-speed photography technology. By defining the Curvature of Curve (COC) of the electrode, we investigated the physical mechanism of the electrode configuration affecting the PSAD disturbed flow field. The results show COC has the optimal solution COCopt. When COC{less than or equal to}COCopt, the smaller the COC, the more concentrated the PSAD disturbances to the flow field. When COC>COCopt, the electrode configuration will have an endpoint effect, resulting in a deviation between theoretical COC and real COC. The larger the COC, the stronger the endpoint effect, and the more concentrated the PSAD disturbances to the flow field. COC affects the disturbance degree of PSAD to the flow field by distorting electric field intensity distribution. The change in electric field intensity causes the fluctuation frequency of the flow field to be inconsistent with the discharge frequency of the PSAD. The stronger the distortion degree of the electric field intensity, the stronger the high-frequency characteristics of the fluctuating frequency of the flow field, and the stronger the high-frequency characteristics of the flow mode of the flow field. In addition, we obtained the value range of COCopt within 0.5~0.7 through theoretical derivation and established a mathematical model of electrode structure's effect on the flow field's flow structure.

Identification of flow structures in a closed chamber in the presence of a needle plasma actuator

“…19 In comparison with other flow control techniques, DBD plasma actuators have lower power consumption; are easy to handle; no movement of mechanical parts; lightweight; inexpensive to build, implement, and maintain; and have high-frequency response permitting real-time operating parameters. [20][21][22] DBD is also known as silent discharge; it is constituted by two different electrodes with a dielectric layer between them. Usually, one electrode is grounded, whereas the other relates to high voltage excitation in the range of kV.…”