【作者】 何麟；

【导师】 李天匀；

【作者基本信息】 华中科技大学 ， 船舶与海洋结构物设计制造， 2007， 硕士

【摘要】 鉴于实际水下结构物在振动过程中受到流场和静水压力共同作用,本文在总结前人工作的基础上,着重探讨了水下圆柱壳在振动过程中受到静水压力影响的情况。本文建立了静水压力作用下耦合系统的频散方程,并结合振动能量流的方法,对水下无限长圆柱壳结构模型的频散和声辐射性能以及能量传播进行了理论分析,分析模型很详尽的考虑了静水压力作用对结构振动的影响,可为水下柱壳类结构物的减振降噪提供一定的参考。文中首先以一流场中无限长圆柱壳自由振动时的频散特性为研究对象。采用Flügge壳体运动方程和Helmholtz声学方程建立静水压力作用下耦合系统的频散方程,利用三点迭代法对该超越方程进行求解,得到传播波的频散曲线。在数值分析中针对不同壳厚比的参数情况进行了分析,并设定三种浸没深度进行比较,得出其在具体条件下的频散特性。发现随水深增加,相应的波数呈上升趋势,等间距加大水深,其浸深绝对值越大影响也越大,图示曲线间距增加。本文又通过壳体振动所产生的三支波的位移比值分析了不同的频率下壳体的振动形式他们实际上是由哪几种波形耦合得到的。接着,本文对水下圆柱壳的声辐射性能进行了分析,研究了水下无限长圆柱壳受到外激励时的声辐射情况。在数值分析计算中,针对不同水深、不同频率、不同周向波数、不同壳厚比的参数情况,对圆柱壳的声辐射性能进行了比较。其中着重讨论了静水压力的影响。鉴于在固液耦合振动的复杂性,考虑到能量流分析的特点,如:对相位值不敏感,在结构中以矢量形式传播,易于理解的物理概念,本文还从能量的角度对水下壳体振动进行了分析。重点考察了静水压力的存在对输入能量流的影响。更多还原

【Abstract】 Given the actual vibration underwater structures in the process of joint action by the flow field and hydrostatic pressure, the paper was focused on the submerged cylindrical shell vibration in the course of being affected by hydrostatic pressure. In this paper, the coupling system under hydrostatic pressure dispersion equation was build. A theoretical analysis of the combination of vibrational energy flow and the sound radiation and dispersion of underwater model of infinite cylindrical shell structure, detailed analysis of the model to consider the effects of hydrostatic pressure on the structural vibration were given, which can be used to the reference of reducing the noise of underwater vibration-shell structure.An infinite cylindrical shell in the fluid field which under the free vibration frequency whose dispersion characteristics was studied. Flügge shell equation of motion and the Helmholtz equation were used to build hydrostatic pressure dispersion equation of coupling system, use the three-pointed iteration to solve Transcendental equations, get the spread of the wave dispersion curves. Numerical analysis in shell thickness of the different parameters of the analysis, comparison and set three submersion depth. come under the specific conditions in the frequency dispersion characteristics. Found with the increase of water depth, the corresponding wave number is rising, and so is enlarged depth, Soak deep absolute greater impact greater icon spacing curves. In this paper, through the shell vibration displacement ratio of the three waves of different frequencies of vibration shell under which actually form the coupling of several waveforms.Then, the paper underwater acoustic radiation properties of the cylindrical shell analysis Research by the underwater infinite cylindrical shell excitation of acoustic radiation. In numerical analysis, different depth, different frequencies, different wave to a few weeks, the shell thickness ratio of different parameters. the radiation properties of the cylindrical shell compared which focused on discussing the hydrostatic pressure.Given the complex nature of the solid-liquid vibration, taking into account the analysis of the energy flow characteristics, such as : the value is not sensitive phase. Vector spread to the structure, easy to understand the physics concept This paper also from the perspective of the underwater energy shell vibration analysis. He inspected the hydrostatic pressure of the existence of imported energy.更多还原