Acoustic wave diffraction at the upper edge of a two-dimensional periodic array of finite rigid cylinders. A comprehensive design model of periodicity-based devices

Abstract

Diffraction at the upper edge of a two-dimensional periodic array of finite rigid cylinders immersed in air as well as the effect on its wave propagation properties are numerically and experimentally reported in this work. The diffraction and the band gap effects, due to the finite length of the cylinders and the periodicity of the array, are the two phenomena that must be taken into account in the design of real devices based on periodicity to control the propagation of waves. We also present a model which allows the separate analysis of each of these two phenomena and provides a comprehensive procedure for designing more efficient devices based on arrays of scatterers, following the concept of tunability developed by some authors.