Scattering from impedance gratings and surface wave formation.
Scattering from impedance gratings and surface wave formation.
复制标题
阻抗光栅和表面波形成的散射。
DOI：
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发表时间：
2002
影响因子：
2.4
通讯作者：
G. Daigle
中科院分区：
文献类型：
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作者：
Wenhao Zhu;M. R. Stinson;G. Daigle
本文研究了刚性表面上梳状阻抗光栅对平面声波的散射问题。基于光栅结构的周期性，提出了均匀平面波入射时的严格解析方法，该方法将平面波入射问题转化为混合边值问题求解，散射场由光栅分隔壁的切向速度差表示。导出了切向速度差的奇异积分方程，可直接用Gauss-Chebyshev方法求解。由此产生的解决方案包括一系列的布洛赫-Floquet波（平面体波和表面波模式）的显式表达式的膨胀系数。当光栅周期远小于入射波长（ka << 1）时，光栅结构等效为平面阻抗面，平面波均匀入射时，光栅结构不能激发表面波。当光栅周期与入射波长相当时，即使在均匀平面波入射的情况下，在一定条件下也可以预测共振现象，并且可以形成表面波。表面波的色散关系也已被检查。本文研究了光栅的阻抗效应对反射波、衍射波以及表面波的色散和形成的影响，其中声硬光栅是一般阻抗光栅的特例。
The scattering problem of acoustic plane waves from comb-like impedance gratings on a rigid surface has been investigated in this paper. A rigorous analytic approach for homogeneous plane-wave incidence is presented based on the periodicity of the grating structure, in which the problem was solved as a mixed boundary value problem and the scattered field was represented by the tangent velocity difference across a partition wall of the grating. A singular integral equation has been derived for the tangent velocity difference, which can directly be solved with the Gauss-Chebyshev procedure. The resulting solution consists of a series of Bloch-Floquet waves (plane bulk wave and surface wave modes) with explicit expressions for the expansion coefficients. When the grating period is much less than the incident wavelength (ka << 1), the grating structure is equivalent to a plane impedance surface and no surface waves can be excited with homogeneous plane-wave incidence. When the grating period is comparable to the incident wavelength, resonance phenomena are predicted under certain conditions and surface waves can form, even with homogeneous plane-wave incidence. The dispersion relation for surface waves has also been examined. The impedance effects of the grating on the reflection and diffraction waves as well as on the dispersion and formation of surface waves have been studied, with the acoustically hard grating being the special case of the general impedance grating.