船舶水下辐射噪声抑制的声振相关性方法

Acoustic-vibration correlation method for suppressingunderwater radiated noise from ships

船舶水下辐射噪声与船体振动的耦合关系是非常复杂的,识别水下辐射噪声与船体振动相关性较高的部位,确定影响水下辐射噪声的关键因素,对降低噪声具有重要工程意义。基于声振耦合分析原理,提出船舶水下辐射噪声抑制的声振相关性方法,探讨了船舶水下辐射噪声与结构振动特性、船上振源的频谱和船体振动响应等的相关性定量评价指标,厘清各因素对水下辐射噪声的影响规律。舱段及拖轮降噪设计示例表明,相关性定量评价指标的计算量小,根据指标值可以高效确定与水下辐射噪声相关性高的结构及影响参数,实现船舶水下辐射噪声的高效抑制设计;通过调整振源附近湿表面的板厚,舱段和拖轮的声功率总级分别降低了5.66 dB和4.84 dB,但振动减小幅度与噪声降低幅度并不是线性的。

Coupling relation between underwater radiated noise and hull vibration is very complex.Identifying positions with high correlation between underwater radiated noise and hull vibration and determining key factors affecting underwater radiated noise have important engineering significance for reducing noise.Here,based on the principle of acoustic-vibration coupled analysis,an acoustic-vibration correlation method for suppressing underwater radiated noise from ships was proposed.Quantitative evaluation indicators for correlations among underwater radiated noise from ship,structural vibration characteristics,frequency spectra of vibration sources on ship and vibration response of ship hull were explored,and effect laws of various factors on underwater radiated noise were clarified.Examples of noise reduction design for cabin and tugboat showed that calculation amount of correlation quantitative evaluation indicators is small;based on indicator values,structure and affecting parameters with high correlation to underwater radiated noise can be efficiently determined to realize efficient suppression design for ship underwater radiated noise;by adjusting plate thickness of wet surface near vibration source,sound power total levels of cabin and tugboat reduce by 5.66 dB and 4.84 dB,respectively;but reducing amplitudes of vibration and noise are not linear.