Negative refraction of ultrasound in a two-dimensional prism-shaped phononic crystal

초록

The present study aims to investigate theoretically and experimentally the negative refraction of ultrasound in a two-dimensional prism-shaped phononic crystal with a square lattice in water. Using the finite element method, we calculated the acoustic band structure along the ΓX direction of the first Brillouin zone of a two-dimensional phononic crystal consisting of periodic square arrays of stainless-steel solid cylinders with radii of 0.5 mm and with a lattice constant of 1.5 mm in water. Based on the calculated band structure, the pressure fields of ultrasound transmitted through the phononic crystal in water were calculated over a wide frequency range from 0.5 to 1.0 MHz by using the finite element method, and they were measured experimentally to validate the predicted results. The positive and the negative angles of refraction obtained by using both the finite element method and the refraction experiment were in good agreement with those calculated by using Snell' s law. © 2016, Korean Physical Society. All rights reserved.

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