Vanaverbeke S, Windels F, Leroy O
Interdisciplinary Research Center (IRC), E. Sabbelaan 53, B-8500 Kortrijk, Belgium.
J Acoust Soc Am. 2003 Jan;113(1):73-83. doi: 10.1121/1.1523081.
Fourier analysis and normal mode theory are used to describe the reflection of bounded inhomogeneous waves on a liquid/solid interface. Nonspecular reflection phenomena in the Rayleigh angle are studied in detail. In this way, an explanation is given for the Rayleigh dip phenomenon for positive inhomogeneity factors and the related result of a reflection coefficient larger than unity when the sign of the inhomogeneity factor is reversed. In the limit of large beamwidths, the reflection coefficient predicted by the infinite plane inhomogeneous wave theory is obtained. These results are entirely consistent with the experimental work published by Deschamps [J. Acoust. Soc. Am. 96, 2841-2848 (1994)]. The energy efficiency of Rayleigh wave excitation is investigated as well. It is shown that for large beamwidths, the energy efficiency for bounded inhomogeneous waves is considerably higher in comparison with Gaussian and square-profiled beams.
傅里叶分析和简正模理论用于描述有界非均匀波在液/固界面上的反射。详细研究了瑞利角处的非镜面反射现象。通过这种方式，解释了正非均匀性因子下的瑞利凹陷现象，以及当非均匀性因子符号反转时反射系数大于1的相关结果。在大波束宽度的极限情况下，得到了无限平面非均匀波理论预测的反射系数。这些结果与德尚发表的实验工作[《美国声学学会杂志》96, 2841 - 2848 (1994)]完全一致。还研究了瑞利波激发的能量效率。结果表明，对于大波束宽度，有界非均匀波的能量效率与高斯波束和方形波束相比要高得多。
