水下结构物低频振动相关性及声辐射特性分析

Analysis on correlations of low frequency vibration characteristics and acoustic radiation of a submerged structure

振动相关性普遍存在于水下结构物低频总振动中。本文基于有限元/边界元理论给出了水下结构物低频振动模型及求解方法,讨论了舷间、舷外附连水以及大型机组基座、舱内铺板、设备等对低频振动特性的影响。在此基础上,研究了推进器通过轴系纵向激励引起结构的低频弯曲振动与纵向振动的相关性,并进行声辐射计算分析。研究结果对理解推进器交变力作用下的水下结构物低频声辐射的形成过程有实质性的意义。

The correlation for different vibration modes widely consists in low-frequency vibration of submerged structures.Based on finite element-boundary element theory,a dynamic submarine model and a numerical solution method have been established in this paper.The influences by interbedded and out added water,big machine bases,deck and equipments on low frequency total vibration modes were discussed.Then the correlation between low frequency total flexural vibration modes（transverse and vertical）and longitudinal vibration modes of a vessel by lengthways inspiriting is illustrated.At the same time,the acoustic radiation characteristics were calculated.The results show that there is a strong correlation at low frequency by lengthways inspiriting.The conclusions given are favorable for submerged vessel acoustic design.