Design and validation of a comprehensive model to characterize sonic crystals acoustic screens in the low frequency regime

Abstract

[EN] In this paper, we present a comprehensive model to obtain numerical/experimental results on the acoustic behaviour of sonic crystals in the low frequency range (up to 1700 Hz). We have focused our attention on this range because it is the most difficult to control in the field of environmental acoustics, and sonic crystals are particularly useful for this purpose. The immediate application is the design of high-tech acoustic screens for traffic noise, although sonic crystals are capable of screening any type of noise due to their scalability. In addition, the model can be used for the analysis of the rich physical behaviour of these metamaterials at these frequencies. The model, completely designed and developed by us, consists of a three-dimensional numerical simulation software together with a real prototype to obtain experimental results. It is precisely the joint use of these two tools that gives our model a unique versatility. To validate the model in this low frequency range, we have considered different sonic crystals where their geometrical parameters, lattice and filling factor have been varied. The accurate results obtained, compared with those obtained in anechoic chamber and with those calculated with other existing numerical models, show that our model works successfully. All this in a simple and low-cost way compared to other existing design techniques and other ways of obtaining experimental results.