水下非圆截面柱壳振动与声辐射特性研究

The circular cylindrical shell structure is widely used in ship and ocean engineering. Most researches on the static and dynamic characteristics of cylindrical shell structure are based on ideal cylindrical shell model, and the researches are comparatively mature. However, the non-circular cylindrical shells are of great use in the underwater structures as well. Meanwhile, the section deviations are always inevitable in the actual manufacturing process of circular cylindrical shell. However the studies on the vibroacoustic characteristics of submerged non-circular cylindrical shell are still quite scarce. Aimed at the submerged elliptic cylindrical shell and eccentric cylindrical shell and other typical non-circular cylindrical shell, the vibroacoustic characteristics of non-circular cylindrical shell coupled with sound field are analyzed by using theoretical analysis, numerical calculation and model test, and the difference of the vibroacoustic characteristics between non-circular cylindrical shell and ideal cylindrical shell is discussed. The intrinsic physical relationship between the characteristic parameters and the vibration and sound radiation of noncircular cross section is revealed, which will provide the theoretical basis for the vibration and noise control of submerged non-circular cylindrical shell. Based on the research, the vibroacoustic model of the typical non-circular cylindrical shell is established in theory, and it further enriches underwater acoustic research of the cylindrical shell structure. Furthermore, the research can also be used to guide the acoustic design of submerged typical non-circular cylindrical shell structure and assess acoustic performance of the cylindrical shell with manufacturing deviations. This project research has important theoretical significance and application value.

圆柱壳结构在船舶与海洋工程中应用广泛，对其静动态特性的研究多是基于理想圆柱壳模型来开展,研究已较为成熟。但是非圆截面柱壳在水下结构中也有较多的应用，且理想圆柱壳在实际加工制造过程会也会产生截面偏差，然而有关水下非圆截面柱壳声振特性的研究至今仍相当匮乏。本研究即以水下椭圆柱壳和偏心圆柱壳等典型非圆截面柱壳为研究对象，采用理论分析、数值仿真和模型试验等手段分析水下非圆截面柱壳与声场耦合的振动与声学特性，探讨非圆截面柱壳的声振耦合特性与理想圆柱壳间的差异，揭示非圆截面的特征参数与其振动和声辐射之间的内在物理联系，为水下非圆截面柱壳的振动与噪声控制提供理论依据。通过本项目研究，在理论上建立起典型非圆截面柱壳的声振模型，进一步丰富水下柱壳结构的声振研究体系；同时研究成果也可用于指导水下典型非圆截面柱壳的结构声学设计和用于评估圆柱壳的制造偏差对声学性能的影响。项目研究具有重要的理论意义和工程应用价值。

水下圆柱壳结构在船舶与海洋工程中应用广泛，对其静动态特性的研究多是基于理想圆柱壳模型来开展,研究已较为成熟。但是非圆截面柱壳在水下结构中也有较多的应用，同时，理想圆柱壳在实际加工制造过程会也会产生截面偏差，有关水下非圆截面柱壳声振特性的研究相当匮乏。.本研究以水下椭圆柱壳和偏心圆柱壳等典型非圆截面柱壳为研究对象，采用理论分析、数值仿真和模型试验等手段系统地开展了水下非圆截面柱壳的振动与声辐射研究工作。. 针对（加肋）椭圆柱壳，基于Flügge壳体理论，将椭圆柱壳位移以双Fourier级数的形式展开，椭圆周向曲率半径表示为无量纲化周向弧长坐标的函数。通过级数变换法、传递矩阵法等方法，考虑流场对椭圆柱壳声振特性的影响，建立了椭圆柱壳-流场耦合系统理论模型。系统研究了静压下椭圆柱壳振动、功率流及声辐射特性，并分析了椭圆度等壳体参数以及静压对椭圆柱壳声振特性的影响。提出了基于内压下椭圆柱壳固有频率与静水压力的关系来预报其弹性失稳临界压力的新方法。开展了椭圆柱壳声振特性的试验研究，通过试验，进一步验证了本文理论模型和求解方法的正确性。. 系统研究了真空中、流场中及静压下偏心柱壳的自由振动、功率流及声辐射特性。根据偏心柱壳截面几何特性，将偏心柱壳转化为周向变厚度圆柱壳。基于波传播法，将壳体位移以双Fourier级数形式展开，周向厚度表示为关于周向弧度的三角函数形式，通过级数变换，建立偏心柱壳的声振理论模型。得出偏心率等相关参数对偏心柱壳声振特性的影响规律。提出了基于内压下偏心柱壳固有频率特性来预报其弹性失稳临界压力的方法。. 通过本项目研究，在理论上建立起典型非圆截面柱壳的声振模型，进一步丰富水下柱壳结构的声振研究体系；揭示了非圆截面的特征参数与其声振特性之间的内在物理联系，研究成果可用于指导水下典型非圆截面柱壳的结构声学设计和用于评估圆柱壳的制造偏差对声学性能的影响。项目研究具有重要的理论意义和工程应用价值。