Anomalous negative reflection of acoustic waves from a two-dimensional phononic crystal immersed in water

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• 作者：Hwi Suk Kang ; Suk Wang Yoon ; Kang Il Lee
• 关键词：Phononic crystal ; Negative reflection ; Angular spectrogram ; Diffraction grating ; Finite element method
• 刊名：Journal of the Korean Physical Society
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：70
• 期：3
• 页码：262-267
• 全文大小：
• 刊物主题：Physics, general; Theoretical, Mathematical and Computational Physics; Particle and Nuclear Physics;
• 出版者：The Korean Physical Society
• ISSN：1976-8524
• 卷排序：70

文摘

In the present study, we experimentally and theoretically demonstrated anomalous negative reflection of acoustic waves obliquely incident upon the boundary of a two-dimensional phononic crystal (PC) consisting of periodic square arrays of stainless-steel cylinders immersed in water. The angular spectrogram showing the frequency as a function of the angle was measured for the reflection from the PC when the incidence angle of the sound beam was fixed to be 20°. To understand the negative reflection from the PC, we considered the boundary of the PC to behave as an acoustic diffraction grating, and we calculated the acoustic pressure fields at specific frequencies of interest by using the finite element method. We found that the grating law could be successfully applied to the boundary of the PC in order to determine the direction of the acoustic waves diffracted in water.