起始冲击波和抑制器抑制效率的比较实验研究

发动机燃气射流产生的起始冲击波对于承载体具有破坏作用，必须采取抑制措施减弱其影响。多孔抑制器就是采用抑制措施之一。该文对具有不同开孔率的超始冲击波抑制器的抑制效率进行了对比实验研究。实验中采用了实验发动机，并且测量了燃气射流所产生的起始冲击波在弧面刚性斜板上的反射压力。通过于子波的分析方法，对压力数据进行了分析，获得了基于子波系数的频带能量谱和冲击波强度指数。提出了评估抑制器抑制效率的2抑制效率，即峰值抑制效率和强度指数抑制效率。研究结果表明，抑制器对火箭导弹发射的起始冲击波有抑制作用，开孔率较小时在近场有较好的抑制效果。

Experimental Comparison of Efficiency of Initial Shock Wave Attenuator

Initial shock wave (ISW) generated by engine exhausted flow field has harmful effect on launch equipment so measures should be taken to attenuate this effect. As one of these measures a perforated attenuator was introduced to repress ISW. Experiment was conducted to compare the efficiency of ISW attenuators with different perforation ratio. Experimental engine was used in the study. Pressure of ISW on rigid arc was measured with piezo-resistance pressure transducers. Pressure data were analyzed by wavelet transform in wavelet domain. Frequency band energy spectrum and intensity index of ISW based on wavelet coefficient were obtained. Peak pressure attenuation efficiency and intensity index attenuation efficiency were defined to evaluate the function of attenuator. Result shows that the attenuator is quite perfect to repress ISW, and lower perforation ratio has better attenuation function in near field for rocket engine.