Pump-jet propulsor excitation transfers to submarine hull along rotor-shaft and duct-stator paths simultaneously. The investigations on the effects of excitation transfer paths on structural vibration and acoustic radiation of submarine are limited. The present work aims to investigate vibro-acoustic characteristics of coupled shaft-submarine hull system utilizing a theoretical wavenumber analysis method and conduct acoustic design. The energy functional of the coupled structure-fluid system of the research object is first developed, and the displacement components of the jointed shell and the acoustic pressure are expanded by the Fourier series along circumferential direction. This allows for obtaining vibro-acoustic responses in the circumferential wavenumber-frequency domain, by which the predominant wavenumbers contributing to acoustic radiation are identified. The discussions reveal that the modes = 0 and = 1 respectively dominate the acoustic radiation under axial and vertical rotor loads. The acoustic radiations under duct-stator load are mainly contributed by mode = 0, and the higher order modes = 1 and = 2 determine several acoustic peaks. Furthermore, two acoustic design schemes are proposed to suppress the wavenumbers with high radiation efficiency. It is proven that the design of the symmetric inner foundation and the application of new material are two efficient ways to improve acoustic performance of the submarine.

中文翻译：

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不同激励传递路径下轴-潜艇体耦合系统的声学特性及衰减


泵喷推进器的激励沿着转子轴和导管定子路径同时传输到潜艇船体。关于激励传递路径对潜艇结构振动和声辐射影响的研究还很有限。本工作旨在利用理论波数分析方法研究轴-潜艇船体耦合系统的振动声学特性并进行声学设计。首先建立了研究对象的结构-流体耦合系统的能量泛函，将节理壳的位移分量和声压沿周向进行傅里叶级数展开。这允许获得圆周波数频域中的振动声学响应，通过该响应识别对声辐射有贡献的主要波数。讨论表明，模式 = 0 和 = 1 分别主导轴向和垂直转子载荷下的声辐射。管道定子负载下的声辐射主要由模态 = 0 贡献，高阶模态 = 1 和 = 2 决定了几个声峰。此外，提出了两种声学设计方案来抑制高辐射效率的波数。实践证明，对称内基础设计和新材料应用是提高潜艇声学性能的两条有效途径。