运行参数对自激脉冲射流特性影响的小波分析

The Influence of Structural Parameters of Under-water Self-excited Pulsed Jet Device on Pressure Fluctuation Based on Lifting Wavelet Transformation

以自激吸气脉冲射流装置冲击试验得到的压力脉动时域波形为基础,运用Savitzky-Golay平滑后的提升小波法对装置内压力脉动及靶心冲击压力脉动进行时频特性分析。结果表明,围压、工作压力和装置是否吸气对装置压力脉动特性影响较大;射流压力脉动随围压的增大逐渐降低,围压低于30 m的射流压力脉动幅值大于围压高于30 m以上的压力脉动幅值;装置内的射流压力脉动随着工作压力的增大逐渐下降,而靶心射流冲击压力脉动随工作压力的增大逐渐上升;装置吸气的射流压力脉动大于装置不吸气的压力脉动,装置吸气时下喷嘴和靶心的射流冲击压力脉动及其脉动频率比较稳定,主频带明显。水下自激吸气脉冲射流装置具有选择、放大和稳定射流压力脉动的功能。

This paper is based on the pressure pulsation time-domain waveform obtained by the impact test of self-excited suction pulsed jet device,the Savitzky-Golay smoothing method be used to time frequency characteristic analysis of the device and target impact pressure fluctuation,andthen,the lifting wavelet method wasused. The results showed that confining pressure,working pressure and inspiration change have obvious influence on device pressure fluctuation characteristic. The jet pressure fluctuation decreases with the increase of the confining pressure,the amplitude of pressure fluctuation of jet under 30 meter is larger than that of 30 meter above the confining pressure. The pressure pulsation in the device decreases with the increase of working pressure,but the pressure pulsation of the target increases gradually with the increase of working pressure. The pressure pulsation of the inspiration of the device is greater than without the inspiration,the pressure pulsation and pulsation frequency of the nozzle diameter and target is relatively stable on device inspiration,andthe main frequency band is obvious. The underwater self-excitation pulsed jet device has the function of selecting,amplifying and stabilizing the pressure pulsation of the jet.