Acoustic characteristics of underwater continuous pulse shock wave

With a view to obtaining the application prospect of metal-sheathed detonating cords in the research of underwater sound sources, an experimental apparatus called underwater continuous pulse wave generator, which can orderly generate a series of shock waves, is designed. On the basis of wavelet analysis, the signal decomposition and reconstruction is implemented to investigate the frequency spectrum characteristics of the signals. Likewise, the sound pressure level of the underwater continuous pulse shock wave is analyzed. Results indicate that the acoustic signal generated by this device has strong acoustic power and high sound pressure level. The frequency contained in the signal is abundant, and the shock waves generated by the detonator and the detonating cord show different frequency spectrum characteristics by the reason of different charge structures and explosion propagation styles. The shock wave generated by the detonator is mainly concentrated in the frequency band of less than 15.6 kHz, and the signal produced by the detonating cord is mainly distributed in the frequency band which is below 62.5 kHz. The pulse shock wave count and acoustic duration of the signal can be controlled by the permutation style and the length of the detonating cord, and the time interval between two adjacent pulse waves is adjustable. The generator is stable and controllable.