船舶水下辐射噪声信号理论模型及仿真

分析典型船舶水下辐射噪声实验数据,获取船舶水下辐射噪声功率谱特征,阐明了准周期随机声脉冲序列信号模型作为船舶水下辐射噪声模型的合理性和普适性,在此基础上,引入爆炸衰减型余弦脉冲信号作为该模型的基本组成单元,给予理论分析,据以数值构建船舶辐射噪声,并与海上试验获取的商船辐射噪声数据进行对比,结果明显一致,证明了该方法的有效性和实用性.

Theoretical model and simulation of ship underwater radiated noise

Ship underwater radiated noise is one of the most important ocean ambient noise sources, and building a reasonable model for the ship underwater radiated noise is helpful for understanding the physical mechanism and reducing research cost of ship underwater radiated noise. The quasi-periodic random sound pulse sequence signals act well in explaining the rhythm and the power spectrum variation of the ship underwater radiated noise, and reveal that there are not any real sinusoidal components in ship radiated noise signals, which come from the non-linear transformation of the signals, and the analysis of some representative experimental data of ship radiated noise also supports this idea. Based on this, the explosion-type cosine pulses are used as the units of quasi-periodic random sound pulse sequences. This model can generate the power spectrum with a peak, and the peak location can change with ship velocity or ship type. The power spectrum variation characteristics of quasi-periodic random sound pulse sequences consisting of the explosion-type cosine pulses are in good agreement with the measured ship underwater radiated noise data, which shows that this model is of important practical value.