A ventilation barrier for low-frequency sound insulation

Abstract

This paper proposes a ventilation barrier for low-frequency sound insulation with a double-opening Helmholtz’s periodic structure. The energy band characteristics of the unit structure and the sound transmission loss of the ventilation barrier are calculated using the finite element method. The research results show that the ventilation barrier exhibits excellent sound insulation in the range of 323–803[Formula: see text]Hz, and the sound insulation band is consistent with the bandgap of the unit structure. In order to reveal the sound insulation mechanism, we have performed a modal analysis of the unit structure. Further, the effects of different dimensional parameters on the structural bandgap are analyzed by changing the structure. The results show that extending the length of the structure inlet or outlet can effectively reduce the start frequency of the low-frequency bandgap, thus achieving the regulation of the sound insulation band. The proposed low-frequency sound insulation ventilation barrier has a simple structure with great application prospects. In addition, the proposed ventilation barrier provides a new idea for noise control in low-frequency ventilation environments.