Acoustic Band Gap of Two Dimensional Array of Helmholtz Resonators

Abstract:

Helmholtz resonator is a sound resonant system,which can consume the external sound excitation.It’s an important sound absorption structure,and can be used as the sound absorption wall in the museum and cinema.A two dimensional array of Helmholtz Resonators was designed,and the finite element method was used to calculate the sound transmission properties.The results show that,such a structure may present the Bragg’s scattering mechanism,local resonance mechanism and the Helmholtz resonance mechanism.Compared to the two dimensional acoustic crystal which is composed of tubes without openings,the structure proposed possesses wider acoustic band gap.So,the noise barriers,acoustic lens can be designed based on such structures.

Key words:acoustic crystals; acoustic band gap; Helmholtz resonator