【作者】 虞悦威；

【导师】 陶钢；

【作者基本信息】 南京理工大学 ， 兵器发射理论与技术， 2004， 硕士

【摘要】 本文对单兵肩射式火箭燃气射流脉冲噪声特性进行了理论分析与实验研究。提出了非线性声学在单兵肩射式火箭燃气射流脉冲噪声特性研究中的运用。指出了传统FFT变换在非稳态信号处理中的缺陷，同时将小波分析理论应用到单兵肩射式火箭燃气射流脉冲噪声信号的分析中，并应用小波变换方法处理单兵肩射式火箭燃气射流脉冲噪声声压—时间历程数据。采用基于小波系数的频带能量谱分析将冲击波噪声和湍流噪声能量集中的频带区分开来。提出了基于最优小波包基的自动软阈值滤波方法在单兵肩射式火箭燃气射流脉冲噪声信号滤波中的应用。 最后，利用上述结论设计了相应的噪声抑制器，并在实验中给予验证。同时通过基于小波系数的频带能量谱分析证明其对冲击波噪声的有效抑制。更多还原

【Abstract】 In this dissertation, academic analysis of impulsive noise in firing-gas jet field of rocket has been researched as well as experimental study. Nonlinar acoustics is applied on impulsive noise in firing-gas jet field of rocket. There are some deficiencies put forward in traditional FFT transform, and wavelet analysis is applied on the signal of impulsive noise in firing-gas jet field of rocket. The frequency bands of turbulence noise and initial shock wave noise are separated by using frequency band energy spectrum based on wavelet coefficient. The filter method of automatic soft-threshold based on optimization wavelet-package is applied on the filtering of signal of impulsive noise in firing-gas jet field of rocket.Finally, the relevant noise attenuator has been designed on the basis of above experimental methods, results, conclusions and analysis technology, identified by experiments.lt is also validated to be effective of decreasing shock wave noise by using frequency band energy spectrum based on wavelet coefficient.更多还原