摘要
研究水中充水有限长圆柱薄壳的声散射。采用弹性薄壳理论结合边界条件导出了有限长圆柱薄壳倾斜入射时散射声场的解析解,内部充水的作用反映在系统总阻抗中增加了内部流体阻抗。数值计算表明,在反向散射声场中,刚性散射部分仅在正横附近有比较大的贡献,而斜入射时起主要作用的是弹性散射部分。散射波相速度频散曲线的计算表明,与内部真空的情况相比内部充水后除正横附近的纵波和剪切波以外,增加了一组内部流体引起的附加波,其对散射声场贡献非常重要。在计算的频率-角度谱图中,内部流体附加波呈现"碗"形共振曲线。
Acoustic scattering from a submerged fluid-filled finite cylindrical shell insonified by an incident plane wave is studied. The analytic solutions of the scattering field are derived using the elastic thin shell theory with the boundary conditions. The fluid-filled impedance adds to the impedance of the system due to the effect of internal fluid. The results show that in the backscattering field, rigid scattering has a large contribution only on the broadside and elastic scattering play a major role when oblique incidence. The dispersion curves of the phase velocity show that except the contribution by longitudinal wave and shear wave near the broadside a series of the additional waves caused by the internal fluid are added which have great contribution to the scattering field. Bowl-shape resonance curves are presented in the frequency-angle spectrum as the contribution of the internal fluid-added wave.
出处
《声学学报》
EI
CSCD
北大核心
2009年第6期490-497,共8页
Acta Acustica
基金
国家自然科学基金资助项目(105004021)
