Experimental Study On The Mode And Characteristics Of Microsecond-pulse Gliding Discharges

As a common form of gas discharges, the gliding discharge can generate a large number of non-thermal plasmas. Compared with gliding discharge driven by traditional AC and DC power, the pulse gliding discharge produced plasma with electronic higher energy, more active, and more rapid ignition. Therefore it has broad application prospects in the field of aviation and other aspects of ignition. Due to the rising edge of pulse power is narrow, which can inhibit the formation of the spark channel. Therefore, this article exploreon discharge form and the transformation law of the microsecond-pulse gliding discharge, in addition to study discharge characteristics and the law of development of the microsecond-pulse gliding discharge. Finally, provide theoretical support for the subsequent application.Changing the applied voltage, a variety of discharge modes can be obtained. Experimental results show that there are three typical discharge modes in microsecond-pulse gliding discharges, i.e. corona discharge, diffuse discharge and spark discharge, respectively. In addition to discharge mode transition among different discharge modes, effect of gas flow, pulse repetition frequency(PRF), and electrode gap on microsecond-pulse gliding discharge was studied. Experimental results showed that the breakdown voltage and ignition voltage of diffuse both decreased with the increase of the PRF, and the breakdown voltage increased with the increase of the gas flow and electrode gap. Maintaining the applied voltage constant, discharge mode can be changed between diffuse discharge and spark discharge as the experimental conditions changing.In this paper, the characteristics of microsecond-pulse gliding discharge is analyzed by electrical characteristics, optical characteristics, and plasma properties. Electrical characteristics is study by measuring voltage, current and calculating the power, energy. Optical characteristics is study by discharge images, grayscale images and spectral curve. Spark channels are gradually dispersed, the discharge region are gradually increased in discharge images with the increase of the PRF, gas flow, and electrode gap. Grayscale images can be quantitatively analyzed discharge image. Also found spectroscopy can characterize the discharge mode. Plasma properties is study by active particle concentration, temperature and impedance. Typical spectral lines, such as N2, N2+ and O, is analyzed.Diffuse discharge and spark discharge minimum impedance respectively 28 k? and 330 ? by calculating. The dirotational temperature and vibrational temperature of diffuse discharge is respectively 360 K and 2850 K by fitting software. The gas temperature of spark discharge reaches 550 K.The development process of the microsecond-pulse gliding discharge is analyzed by Comsol emulation, ICCD, high-speed cameras and schlieren. The development process of diffuse discharge is analyzed by Comsol emulation and ICCD. Both the development process of spark discharge and a single cycle variation of gliding discharge are analyzed by high-speed cameras and schlieren. Experimental results showed that the development process of diffuse discharges is divided four stages by positive streamer theoretical explanation. Single Channel spark is duration of about 33 μs, and the spark channel is discontinuous. The development process of gliding discharges is divided three stages. And found that the emergence of a shortcut channel, in addition to the spark channel width increases under the action of magnetic force.