Abstract
During the last decades, noise has become an environmental problem of the first order. One of the most usual methods to reduce the noise level during its transmission is the use of Acoustic Barriers. In the last few years, an interesting alternative to classical ones formed by a continuous layer of different materials is the use of arrays of isolated scatterers embedded in air, usually called Sonic Crystals. The main noise control mechanism of these barriers is Braggs diffraction due to a Multiple Scattering process, which produces attenuation frequency bands determined by the geometry of the array. Several studies have shown the possibility of increasing the noise control capabilities of Sonic Crystals by adding new attenuation mechanisms such as absorption or resonances. Here we present a practical comprehensive model based on the Finite Elements Method to design this kind of barrier, taking into account all the acoustic factors involved, such as the diffraction on the upper edge or the addition of new attenuation mechanisms. An example of reduction of this diffracted pressure using interference mechanisms is also presented. This model is a step forward in the technological development of Sonic Crystals in the fight against noise.
