Rocket Missile Launch Noise Experiment With Rejection Techniques

In this dissertation, a serial of experimental study of rocket launching noise has been presented, and a new method in processing time history data with rocket noise based on wavelet has also been developed. The thesis consists of four parts.Firstly, the basic principium of acoustics is introduced. The source and characteristics of rocket launching noise are summarized.Secondly, the generation process rocket launching noise and its relationship with rocket exhaust has been gained by experimental study of free exhaust. Its formation and developing mechanism is deduced. In the meantime, the rocket launching noise correlated a Mach reflection, shock wave addition, and the second deflagration is found, and the position change on corresponding position of the impinged object and rocket engine. This result provides experiment reference to attenuator design.Thirdly, time and frequency domain methods in analysis rocket launching noise data are summarized. Wavelet analysis is applied on unsteady rocket launching noise data process.Finally, a practical engineering problem is studied by using of above experiment methods, result, conclusion, and analysis technology. Rocket launching noise with suppression devices is studied by experiment. In course of experimental study of rocket noise, we have designed the attenuator about rocket noise, and have gained a satisfactory result.