New Acoustic Structure Of Their Broadband Noise Reduction Mechanism

With the development of industry and national defense, and the improvement of the human living standards, noise gradually becomes a serious pollution, which needs an urgent solution and receives more and more attentions from scientists and engineers. In reality, we often suffer from the interference of low-frequency and broadband noise, which has a bad influence on human health, and more seriously, probably affects the normal operation of machines and leads to serious accidents. Therefore, it is badly urgent to control the pollution of low-frequency and broadband noise.Some measurements of noise reduction, sound absorption and insulation are usually used to control noise pollution. To effectively absorb and insulate low-frequency and broadband noise, the present paper proposed a new acoustic structure, which combines resonator absorption structure with extended necks, special sound insulation and sound absorption material. The new structure named as Helmholtz Resonator with new absorption materials was studied, and the theoretic analysis and simulation were also conducted. After investigating the broadband resonator absorption structure, we analyzed the sound absorption properties of this structure on the application of wall sound absorption. The influence of geometric parameters on the new Helmholtz Resonator with new absorption materials and extended necks, and the influence of different combination on broadband resonator absorption structure were discussed respectively with the help of theoretic analysis and simulation. Based on the results obtained, the insulation properties of multi-functional complex acoustic structure were further studied with varied thickness of air layer and different insulation materials. Finally, the acoustic structure was analyzed, which combined broadband resonator absorption structure, special insulation structure, and high-performance absorption materials. This structure is the integration of sound absorption and insulation in one structure. We optimized the structural parameters and simulated the sound absorption properties. The good...