Study On The Design Method Of Labyrinth Sound Absorption Structure With Micro-perforated Plates

With the rapid development of modern industry,science and technology,a lot of environmental pollution was produced in the process of modernization.As one of the major sources of pollution,noise pollution has a growing influence on daily production and life.Through effective control measures to eliminate the noise pollution has an important application value.However,traditional sound absorbing materials which could achieve better sound absorption effect in the field of medium and high frequency needed a thick structure to absorb low-frequency sound wave,which is not suitable for actual production.Microperforated plate absorption(MPA)has simple structure and its absorption coefficient can be calculated accurately.The processing materials of the plate were not limited,different plates could be selected according to different purposes.By selecting appropriate design parameters,a better effect of low-frequency sound absorption performance could be achieved,and the thickness of structure is thinner than that of porous materials.So,MPA has a good application prospect in the field of low frequency broadband sound absorption.A labyrinth sound absorption structure with embedded multi-layer micro-perforated plates was proposed in this paper.The sound absorption coefficient of the single-layer micro-perforated plate was calculated by Maa’s theory of micro-perforated plate,and the influence of the main design parameters of the micro-perforated plate on the curve of the sound absorption coefficient was analyzed.Combined with the acoustic transfer analysis method(ATA),the calculation model of the sound absorption coefficient of the multi-layer micro-perforated plates was established.The particle swarm optimization algorithm is used to optimize the sound absorption coefficient curve of the micro-perforated plates absorber to obtain the optimal design parameters.Through the finite element simulation of the impedance tube,the transfer function method is used to calculate the sound absorption coefficient curve of the straight tube and various labyrinth structures,and the influence of the labyrinth structure were obtained.The ATA method was used to analyze the calculation model of the sound absorption coefficient of the elastic micro-perforated plates under different boundary conditions,and the influence of the boundary conditions on the sound absorption coefficient of the elastic micro-perforated plate was studied and rationally used.The impedance transfer method was used to establish the calculation model of the sound absorption coefficient of themulti-layer micro-perforated plates connected by viscoelastic materials,and the effect of the viscoelastic material on the sound absorption coefficient was studied.By establishing theoretical model,optimizing design parameters and global simulation of various labyrinth structures,a design method for a labyrinth sound absorption structure with embedded micro-perforated plates was proposed,which can achieve efficient sound absorption at 30Hz~4000Hz.