充水圆柱壳声散射的环绕波分析

研究了内部充水圆柱壳散射声场的构成。采用弹性薄壳理论和Sommerfeld-Watson变换(SWT)方法导出散射声场的解析解。数值搜索环绕波的复波数极点,比较圆柱壳体内部真空和内部充水两种情况下表面环绕波的相速度、衰减等性质。用镜反射波和环绕波的叠加合成反向散射形态函数,与简正级数解符合良好。计算流体附加环绕波的回波时序并与实验数据对照。结果表明,流体附加环绕波的再辐射是内部充水圆柱壳的形态函数出现更加丰富的共振峰和回波结构形成的重要原因。

Analysis of circumferential waves on a water-filled cylindrical shell

The structure of scattering field from a water-filled cylindrical shell is studied.The analytic solutions of scattering field are derived using elastic thin shell theory and Sommerfeld-Watson Transformation (SWT) method.Complex wave-number poles of circumferential waves are found numerically,the phase speed and attenuation of circumferential waves between the situation of a hollow cylindrical shell and a water-filled cylindrical shell are compared.The synthesis of backscattering form functions which are sum of specular reflection component and circumferential waves is consistent with normal mode result.The computed echo's arrive time sequences of additional fluid circumferential waves are compared with experimental results.The results show that richer resonance peaks appeared in the form functions of a water-filled cylindrical shell and the formation of echo's structure are due to re-radiation effects of additional fluid circumferential waves.