声学覆盖层对锥柱组合结构水下振动噪声的影响

Influence of Acoustic Coating on Underwater Vibration & Acoustic Characteristic of a Compound Cylindrical & Cone Structure

基于统计能量法研究声学覆盖层对锥柱组合结构水下振动噪声的影响。研究结果表明,覆盖层敷设方式、结构损耗因子对声学覆盖层抑振降噪效果有较大影响,当声学覆盖层敷设在结构振动主导传递途径中时,其对传递途径下游结构的抑振效果较为明显,而对振源及传递途径上游结构的振动影响不大,且其抑振降噪效果随敷设密度的增加而增大;损耗因子较小时,声能将从未敷设区域"泄漏"出来,出现"声泄漏"现象,导致声学覆盖层降噪效果下降;随着损耗因子的不断增大,"声泄漏"现象逐渐得到缓解,但声学覆盖层抑振降噪效果有所下降。

Influence of acoustic coating on the underwater vibration ＆ acoustic characteristic of a compound cylindrical ＆ cone structure （CCCS） is researched based on SEA （StatistiCal Energy Analysis） method. The result indicates that the arrangement of acoustic coating and damping loss factor of CCCS have significant influence on the capacity of vibration and noise reduction of acoustic coating to the CCCS. Acoustic coating can reduce the vibration and noise level of the CCCS. Vibration reduction effect is remarkable to the downstream structure, but it is neglectable to the upstream if the acoustic coating is arranged on the main stream of vibration transmission. Vibration ＆ noise reduction capacity of acoustic coating is proportional to the covering density. The result also indicates that damping loss coefficient has effect on the noise reduction capacity of the acoustic coating. Noise will leak out from regions uncovered if damping loss coefficient is rather small, which will inevitably decrease the noise reduction capacity of acoustic coating. The ＂noise leaking＂ phenomenon is loosening with the increase of damping loss coefficient, while the vibration ＆ noise reduction capacity of acoustic coating decreases.