摘要
基于镜像原理,分别建立了计及散射影响与只考虑辐射影响时近水面有限长圆柱壳耦合振动模型,即散射模型和辐射模型。采用Graf定理将虚源声压转换到实源坐标系,再结合能量泛函变分方法,最终推导出壳-液耦合振动的控制方程,求解该方程即可得到结构固有频率。通过对比两类模型自振特性,发现散射模型的同阶次固有频率大于辐射模型,并且随着浸没深度逐渐增大,散射对自振特性的影响逐渐减弱。
Based on the image theory, for the submerged finite-length cylindrical shell close to the free water surface, a scatter-ing coupled vibration model is established by considering both the acoustic scattering and radiation while a radiation coupled vi-bration model is obtained by only considering acoustic radiation. The Graf theorem is used to transform the sound pressure from the image source into the coordinate system of the real source. The coupled vibration equation is deduced with the varia-tional principle, and the natural frequency of the cylindrical shell can be obtained by solving the equation. It is found that the natural frequency of the scattering model is higher than that of the radiation model for the same order. In addition, with the immersion depth gradually increasing, the influence of the acoustic scattering on the free vibration characteristics gradually weakens.
出处
《振动工程学报》
EI
CSCD
北大核心
2017年第5期730-737,共8页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目(51579109
51479079
51379083)
中央高校基本科研业务费资助项目(HUST:2016YXZD010)
关键词
船舶振动
声辐射
散射
镜像原理
能量泛函变分
ship vibration
acoustic radiation
scattering
image theory
energy functional variation principle
