海底阻抗对浅海波导中椭球体的声散射研究(英文)

Studies on Scattering from Ellipsoids in a Shallow Water with sea bottom impedance

基于Greenberg方法推导了含有阻抗边界条件的浅水Green函数,利用边界元法研究了含阻抗的三维海洋波导与散射体相互作用的问题。分析了海底阻抗对声波与结构体相互作用时的散射特性影响,数值分析表明:含有阻抗边界条件的浅海目标的散射特性与理想海底明显不同,海底阻抗对水平断面以及垂直断面的散射场都有一定的影响,目标距离海底越近,场点散射声压受海底边界条件的影响越大;阻抗越大,散射声压越大。指向性的分布对受海底阻抗的大小比较敏感。分析浅海声散射时,海底阻抗的影响不可忽视。

Based on Greenberg＇s derivation a new shallow water Green＇s function for sea bottom with impedance boundary condition is derived.The interaction of acoustic wave with the scattering ellipsoids object in an ocean wave-guide was examined by using BEM.The effect of impedance boundary on the scattering characteristics of the acoustic wave by an ellipsoid obstacle was consid- ered and the results show that the scattering characteristic of ellipsoids in shallow water with impedance boundary condition is different from that of rigid sea bo^ttom.The impedance boundary condition affects both the horizontal propagation and vertical propagation greatly.The scattering pressure will greatly increase if the object is close to sea bottom or the impedance is large.Sound field distribution is sensitive to the impedance of the sea bottom.The effect of impedance boundary condition on scattering characteristic by an obstacle in shallow water wave-guide is prominent.