Study Of Surface Dielectric Barrier Discharge Characteristics Driven By Nanosecond Pulse

Nanosecond pulsed surface dielectric barrier discharge(SDBD)which is one of the important forms of gas discharge has excellent electrical and aerodynamic properties,and has been widely used in aerospace and other fields.How to optimize the electrical performance of SDBD and improve the flow control ability is a difficult problem.Therefore,based on the National Natural Science Foundation of China(51577177)and the Fundamental Research Funds for the Central Universities(2016ZZD07),the electrical and flow characteristics under different pulse parameters and pressure parameters are well studied.Firstly,a series of experiment measurement systems for nanosecond pulsed SDBD are built to study the effect of rise time and pulse width on the electrical properties and induced shock wave characteristics in air.The results show that the pulse current,power,energy and discharge uniformity are closely related to the rise time,but not to the pulse width.The rise time has a great influence on the intensity and propagation velocity of the circular arc shock wave induced by the actuator,and the maximum propagation velocity can reach up to 408 m/s.Meanwhile,the actuator operated with microseconds of pulse width can produce two groups of shock waves.Secondly,the low-pressure simulation system is built to study the effect of pressure on the electrical and spectral characteristics for enhanced nanosecond pulsed SDBD.The results show that the plasma length is determined by both the pressure and the DC voltage,and the excitation DC voltage for surface sliding discharge becomes low with low pressure.Under the combined action of excitation voltage and pressure,there are three modes of discharge,that is,two-electrode SDBD,surface sliding discharge and spark discharge.In addition,the emission spectral intensity of actuator increases with the decrease of the pressure,and the pressure has a great influence on the plasma temperature.Finally,the particle image velocimetry system is used for the study on the nanosecond pulsed SDBD flow characteristics with different pulse parameters and pressure parameters.The results show that rise time,repetition frequency and DC voltage have great influence on the intensity of induced vortex,the disturbance area of induced vortex and the velocity of wall jet.And two induced vortexes are produced by the actuator at the rise time of 50 ns.In addition,with the decrease of pressure,there is an evolvement rule for streamline: the shape of “I”?the shape of “?”(“?”)?the shape of “?”(“?”),and the jet changes from vertical deflection to the left deflection,and the velocity of jet increases gradually.To sum up,the uniform and stable low-temperature plasma can be obtained by the optimization of pulse parameters,and the aerodynamic excitation effect can be improved.At the same time,study on the characteristics of nanosecond pulsed surface dielectric barrier discharge in low pressure environment,is of great significance for the practical application and popularization of surface dielectric barrier discharge flow control.