纳秒脉冲等离子体合成射流激励器的流场特性分析

采用一台高重频、快上升沿纳秒脉冲电源作为激励源，对典型的双电极合成射流激励器进行放电，通过粒子图像测速法（particle image velocimetry，PIV）测量放电实验中激励器稳定流场特性以及发展速度.分析实验结果发现，随着重复频率的提高，合成射流的平均发展速度也随之增大，1 kHz时的平均速度最高达到28.28 m/s，并在单脉冲能量远低于微秒脉冲的情况下，实现了更快的稳态流场控制，表明高重复频率下，更多次数的脉冲放电可提高激励总能量，有效地弥补纳秒脉冲单脉冲输出能量不足的缺点.而且频率越高，流场发展速度越快，说明高重频工作模式会对输出总能量有补偿作用. 

Analysis of Flow Field of Nanosecond Pulsed Plasma Synthetic Jet

A high frequency and steep front nanosecond pulse power source was used as the excitation source to discharge a typical dual-electrode structure synthetic jet actuator.Particle image velocimetry(PIV)was used to measure the characteristics and development speed of the external stable flow field of the actuator in the discharge experiment.The results show that the average development velocity of the synthetic jet increases with the increase of repetition frequency,and the maximum average velocity at 1 kHz reaches 28.28 m/s.In the case that the energy of single pulse is much lower than that of microsecond pulse,a faster steady state flow field control is realized.This indicates that the total excitation energy can be increased with more times of pulse discharge at a high repetition frequency,which effectively makes up for the shortage of energy output of single nanosecond pulses.The flow field develops faster with higher frequency,which indicates that the high frequency operating mode can compensate the total output energy.