脉冲等离子射流在空气中扩展特性的测量与分析

为了分析脉冲等离子射流在空气中的扩展特性,采用压电式压力传感器及数字高速录像系统,研究了等离子发生器产生的脉冲等离子射流的扩展过程。用Photoshop等软件处理获得了不同放电电压及喷射破膜压力下,脉冲等离子射流在大气中扩展的体积、轴向位移、径向位移随时间的变化关系。结果表明,脉冲等离子射流扩展时,其形状由初始的类椭球形状逐渐伸展成一个类圆锥头部加细长的类柱形尾部。射流轴向扩展位移始终大于径向位移。扩展的体积随时间呈单峰分布。增大放电电压和喷射破膜压力均可提高射流的扩展能力,且放电电压越大,等离子射流扩展时的湍流掺混越剧烈。

Measurement and Analysis of the Expansion Characteristics of Pulsed Plasma Jet in Air

To analyze the expansion characteristics of pulsed plasma jet in air, the expansion process of pulsed plasma jet generated by a plasma generator was studied by a piezoelectric pressure sensor and a digital high-speed video system. The relation of change in the extended volume, axial displacement and radial displacement of pulsed plasma jet in atmosphere with time under different discharge voltage and jet breaking pressure was treated and obtained by Photoshop software. Results show that when the pulsed plasma jet is expanded, its shape is gradually extended from the initial shape like ellipsoid to a conical head and an elongated cylindrical tail. The axial displacement of the jet is always larger than the radial displacement. Extended volume reveals a single peak distribution with time. Increasing the discharge voltage and jet breaking pressure can improve the expansion ability of the jet, and the larger the discharge voltage, the more violent the turbulent mixing in the plasma jet expansion.