Discharge and electrothermal efficiency analysis of capacitive discharge plasma synthetic jet actuator in single-shot mode

Gas discharge plasma techniques have been applied successfully in a wide range of fields. As one of these techniques, plasma synthetic jet (PSJ) actuator shows promising application in high-speed flow control. However, for practical application to aircraft, the capacity of the power source is very limited. So the energy efficiency optimization of PSJ actuator is vital to its longtime effective performance. The overall efficiency of PSJ actuator can be divided into three parts: discharge efficiency, electrothermal efficiency and exhaust efficiency. In this paper, discharge and electrothermal efficiencies of a home-designed and manufactured two-electrode PSJ actuator working in single-shot mode and normal atmosphere are evaluated experimentally. The influence of circuit parameters and actuator configurations are investigated and analyzed as a reference for optimization. The results show that, discharge efficiency is basically determined by the resistance ratio of the RLC circuit. The parasitic resistance of the circuit has a great influence on discharge efficiency due to the very short length and low resistance of the plasma arc (O (100 m Omega)). Electrothermal efficiency seems to be less affected by the circuit parameters and actuator configurations compared to discharge efficiency. The variation extent of electrothermal efficiency is around 50-70% for the tested conditions. Smaller discharge chamber volume produces PSJ with higher speed, but will reduce electrothermal efficiency. For a certain overall input energy required, a design of smaller capacitance and wider anode-to-cathode distance is highly recommended to increase both discharge efficiency and electrothermal efficiency. (C) 2019 Elsevier B.V. All rights reserved.