为了对大推力火箭发射时产生的噪声特性进行预测,采用了小型固体火箭发动机来开展缩比实验研究。通过小波变换和FFT方法对实验测得的噪声数据进行深入分析后发现:在发动机工作时间段出现了低频高幅冲击波成分,其幅值和频率特性与典型射流宽带噪声有很大不同;滤掉该冲击波成分之后的噪声频谱是典型的湍流宽带噪声频谱,并且得到射流噪声的声效率为0.51%,很好的吻合了火箭发射时声效率的经验数据,由此证明该冲击波成分并不属于射流噪声。

In order to predict characteristics of high-thrust rocket launching noise, a sub-scale solid engine was chosen for experiment. The wavelet transform and FFT methods were used in processing experimental noise data, the following results can be found out: the low-frequency and high-amplitude shock components are found in the engine's working time, and their amplitude and frequency are very different from classic jet broadband noise; The filtered noise spectrum is typical turbulent broadband noise spectrum, and the sound efficiency of jet noise is 0.51%, which is in good agreement with empirical data of rocket launching, so it can be concluded that shock noise is not a part of jet noise.