Metamaterials acoustic barrier

Abstract

Metamaterials represent a new technology in noise control fields. The first studies about metamaterials date back to the 1900s. The ability to deflect acoustic waves is due to the geometric of the structures that generate resonance effects, and to the periodic arrangement within the material. In this paper, the sound attenuation of an acoustic barrier made with metamaterial was investigated. Compared to the real size, a 1:10 scale model was built using cylindrical wooden bars, 30 cm high and 1.5 cm in diameter. The barrier was investigated for different alternating rows of cylindrical bars, spacing each bar with an empty space to create regular geometries. The insertion loss of each configuration is reported in frequency domain. Furthermore, this configuration could be used for the realization of acoustic filters for the noise control of air conditioning systems (HVAC) and the noises generated by rotating elements.