This study presents a comprehensive Chebyshev-Fourier spectral method for analyzing the free and forced vibroacoustic characteristics of submerged fluid-filled cylindrical shells in heavy fluids. The vibroacoustic interaction system of submerged cylindrical shells consists of three discrete regions: The Sanders shell theory is applied for the shell structure, whereas the wave equation is used to determine the fluid inside. The external fluid pressure on the shell is described using the Helmholtz boundary integral equation. The governing equations for the shell's motion, the formulation of the external fluid pressure on the fluid-structure-interaction (FSI) surface using first-class Chebyshev polynomial and Fourier series expansions, and the internal sound pressure employing two-dimensional Chebyshev polynomial and Fourier series expansions, are seamlessly integrated with Gauss-Chebyshev-Lobatto sampling techniques. Artificial springs are implemented to replicate the boundary conditions of the cylindrical shell. The precision of the proposed methodology is corroborated by comparisons with existing literature and finite element method (FEM) results. Furthermore, the research examines how the properties of the acoustical medium on the vibroacoustic responses of the cylindrical shell. Results indicate that the presence of air inside the shell slightly influence on its acoustic radiation. However, replacing the internal medium with water significantly alters the shell's original radiation characteristics.

中文翻译：

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水下充液圆柱壳的振动声学分析

本研究提出了一种综合切比雪夫-傅里叶谱方法，用于分析重流体中浸没流体填充圆柱壳的自由和受迫振动声学特性。水下圆柱壳的振动声相互作用系统由三个离散区域组成：桑德斯壳理论应用于壳结构，而波动方程用于确定内部流体。使用亥姆霍兹边界积分方程描述壳体上的外部流体压力。壳体运动的控制方程、使用一级切比雪夫多项式和傅里叶级数展开式在流体-结构相互作用 (FSI) 表面上表示外部流体压力，以及使用二维切比雪夫多项式和傅里叶级数展开的内部声压系列扩展，与高斯-切比雪夫-洛巴托采样技术无缝集成。使用人造弹簧来复制圆柱壳的边界条件。通过与现有文献和有限元方法（FEM）结果的比较，证实了所提出方法的精度。此外，该研究还研究了声学介质的特性如何影响圆柱壳的振动声学响应。结果表明，壳体内空气的存在对其声辐射影响较小。然而，用水替换内部介质会显着改变外壳的原始辐射特性。