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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 mΩ)). 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.

A formation criterion of dual synthetic jet (DSJ) is proposed. A DSJ actuator, featured by two cavities, one oscillatory diaphragm, and two exits is a real zero-net mass-flux actuator and has the superiority of higher energy utilization efficiency. However, self-support phenomenon which is unique to DSJ may result in weak jets or even no jets. Two-dimensional numerical simulations have been conducted to investigate the formation characteristics of DSJ. Based on analysis of transverse motion, a dimensionless parameter Stk is drawn out as well as the jet formation criterion of π4a/s 420. A different velocity boundary condition also has been tested and the results conform to the proposed jet formation criterion too. The formation criterion and characteristics can serve as a useful design guide for DSJ.

Based on the unique characteristics of the synthetic-jet flow-field and the attributes of the synthetic-jet actuator, a novel valve-less synthetic-jet-based micro-pump was presented; it is composed of a synthetic-jet actuator, a dividing-clapboard and a mesh filter. The working principle of the micro-pump are novelty and simpleness, it can resolve the main problems of fluid leakage and dust clogging on a micro-pump inlet/outlet nozzle, and it can also be employed as an active flow control device and a micro-thruster. And the basic design criterions of dividing-clapboard and mesh filter were obtained by analyzing the synthetic-jet flow-field. Then, the flow-fields of the micro-pump at the dividing-clapboard on and off design conditions were simulated and compared. The results show the work efficiency of the micro-pump on design condition is high and the designing criterions of the dividing-clapboard satisfy the requirements of maximum flux for the micro-pump, and compared with other reciprocating micro-pumps, the synthetic-jet-based micro-pump mass flow rate on inlet and outlet both are inimitable and invariable positive. The basic design criterions of dividing-clapboard have the additional benefits of designing and adjusting the position of dividing-clapboard to satisfy the claims of pump flux and fluctuation.