Development and Optimization of Broadband Acoustic Metamaterial Absorber Based on Parallel–Connection Square Helmholtz Resonators

Abstract

An acoustic metamaterial absorber of parallel–connection square Helmholtz resonators is proposed in this study, and its sound absorption coefficients are optimized to reduce the noise for the given conditions in the factory. A two–dimensional equivalent simulation model is built to obtain the initial value of parameters and a three–dimensional finite element model is constructed to simulate the sound absorption performance of the metamaterial cell, which aims to improve the research efficiency. The optimal parameters of metamaterial cells are obtained through the particle swarm optimization algorithm, and its effectiveness and accuracy are validated through preparing the experimental sample using 3D printing and measuring the sound absorption coefficient by the standing wave tube detection. The consistency between the experimental data and simulation data verifies feasibility of the proposed optimization method and usefulness of the developed acoustic metamaterial absorber, and the desired sound absorption performances for given conditions are achieved. The experimental results prove that parallel–connection square Helmholtz resonators can achieve an adjustable frequency spectrum for the low frequency noise control by parameter optimization, which is propitious to promote its application in reducing the noise in the factory.

Development of Adjustable Parallel Helmholtz Acoustic Metamaterial for Broad Low-Frequency Sound Absorption Band

“…In order to obtain the desired sound absorption performance, it is essential to adjust structural parameters of the acoustic metamaterial [ 15 , 16 , 17 , 18 , 19 ]. Li et al [ 15 ] had proposed the composite structure composed of porous-material layer mosaicked with a perforated resonator and its structural parameters were optimized to enhance the low-frequency sound absorption of the porous layer.…”

“…A Helmholtz-type phononic crystal with adjustable cavity structure and labyrinth tubes was designed by Han et al [ 18 ], and multiple resonant band gaps could be connected by adjusting the structural layout of the cavity through the telescopic screw, so as to achieve the purpose of widening the band gap and the active control of environmental noise. Wang et al [ 19 ] had developed an acoustic metamaterial absorber of parallel-connection square Helmholtz resonators, and the average actual sound absorption coefficients of these three optimized metamaterial cells were 0.9271 in the [700 Hz, 1000 Hz] with a total size of 30 mm, 0.9157 in the [600 Hz, 900 Hz] with a total size of 40 mm, and 0.9259 in the [500 Hz, 800 Hz] with a total size of 50 mm, respectively. It has been proved that optimization design is essential and effective method to achieve low frequency noise control with broadband for the acoustic metamaterial.…”

Research on the Sound Insulation Performance of Composite Rubber Reinforced with Hollow Glass Microsphere Based on Acoustic Finite Element Simulation

“…In order to improve the research efficiency and reduce the experiment cost, the acoustic finite element simulation has been widely utilized in the field of sound insulation and noise reduction [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Okuzono et al [ 30 ] applied the finite element method using hexahedral 27-node spline acoustic elements with low numerical dispersion for the room acoustics simulation in both the frequency and time domains.…”

“…Sathyan et al [ 32 ] proposed a numerical method combining both the finite element method and boundary element method for the acoustic noise of electromagnetic origin generated by an induction motor. In order to improve the research efficiency, Wang et al [ 33 ] used a two–dimensional equivalent simulation model to obtain the initial value of the parameters and a three–dimensional finite element model to simulate the sound absorption performance of a metamaterial cell. The finite element analysis procedure was selected by Abdullahi and Oyadiji [ 34 ] to simulate wave propagation in air-filled pipes, which was essential in the study of wave propagation in pipe networks such as oil and gas pipelines and urban water distribution networks.…”

“…Acoustic finite element numerical simulation analysis of the sound insulation hood model was carried out using the acoustic software LMS Virtual Lab Acoustics by Wu et al [ 39 ], and the simulation result was verified by the experimental validation. It has been proved by these literatures [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ] that the acoustic finite element simulation is an effective and helpful method to analyze the sound characteristics of materials or structures through selecting the suitable mesh type and appropriate element parameters, which is propitious for improving research efficiency and reducing the experimental steps and costs.…”