The control system modeling of low-frequency acoustic energy to reduce

Abstract

According to the physical characteristics of the marine structure and acoustic wave propagation characteristics, in order to reduce underwater noise, a feedback control model of acoustic nonlinear interaction is established in this paper. The power spectrum and the acoustic energy changing characteristics of single-frequency acoustic wave, which has been through the nonlinear module, and the amplifier module, are analyzed respectively. This lays the foundation for the feedback control model of acoustic nonlinear interaction. Using the chaotic dynamics method, the simulation on the time-history chart, the phase diagram, the power spectrum and the maximum Lyapunov exponent of single-frequency acoustic wave, which go through the feedback control system under external excitation, is analyzed. The result of the simulation shows that, under the control system, the single-frequency acoustic wave amplitude values are modulated, the phase diagram is disorganized, the power spectrum shows the continuous broadband spectral characteristics, the maximum Lyapunov exponent is greater than zero, what's more, the greater the frequency of the external disturbance acoustic is and the smaller the amplitude is, the greater the reduction value of the acoustic energy of the low-frequency acoustic waves under the control system is. Therefore, the dynamic model of the single-frequency acoustic energy reducing in the marine media, in other words, the nonlinear feedback control system under the disturbance of the external excitation and high frequency and the small amplitude, takes shape initially.