Hewett David P, Morris Aaron
Mathematical Institute, Radcliffe Observatory Quarter, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom.
J Acoust Soc Am. 2015 Feb;137(2):633-9. doi: 10.1121/1.4906265.
This paper concerns the frequency domain problem of diffraction of a plane wave incident on an infinite right-angled wedge on which impedance (absorbing) boundary conditions are imposed. It is demonstrated that the exact Sommerfeld-Malyuzhinets contour integral solution for the diffracted field can be transformed to a line integral over a physical variable along the diffracting edge. This integral can be interpreted as a superposition of secondary point sources (with directivity) positioned along the edge, in the spirit of the edge source formulations for rigid (sound-hard) wedges derived by Svensson et al. [Acta Acust. Acust. 95, 568-572 (2009)]. However, when surface waves are present the physical interpretation of the edge source integral must be altered: it no longer represents solely the diffracted field, but rather it includes surface wave contributions.
本文关注平面波入射到施加了阻抗（吸收）边界条件的无限直角楔形体上的频域衍射问题。结果表明，衍射场的精确索末菲 - 马柳日涅茨围道积分解可转化为沿衍射边缘的一个物理变量的线积分。按照斯文森等人[《声学学报》95, 568 - 572 (2009)]推导的刚性（声硬）楔形体的边缘源公式的思路，该积分可解释为沿边缘定位的次级点源（具有方向性）的叠加。然而，当存在表面波时，边缘源积分的物理解释必须改变：它不再仅仅代表衍射场，而是还包括表面波的贡献。
