Mohammad Javad SheikhMozafari^*

Sound & Vibration, Vol.58, pp. 81-100, 2024, DOI:10.32604/sv.2024.048897

Abstract Mitigating low-frequency noise poses a significant challenge for acoustic engineers, due to their long wavelength, with conventional porous sound absorbers showing limitations in attenuating such noise. An effective strategy involves combining porous materials with micro-perforated plates (MPP) to address this issue. Given the significant impact of structural variables like panel thickness, hole diameter, and air gap on the acoustic characteristics of MPP, achieving the optimal condition demands numerous sample iterations. The impedance tube’s considerable expense for sound absorption measurement and the substantial cost involved in fabricating each sample using a 3D printer underscore the advantage of utilizing simulation methods to… More > Graphic Abstract

Si Chen¹, Yuhao Zhou¹, Sarah Mohrmann², Haiyan Fu¹, Yuying Zou¹, Zheng Wang^1,*

Journal of Renewable Materials, Vol.10, No.11, pp. 2791-2803, 2022, DOI:10.32604/jrm.2022.021531

Abstract Based on the efficient sound absorption characteristics of Helmholtz resonance structures in the range of medium and low frequency acoustic waves, this paper investigates an effective solution for light timber construction walls with acoustic problems. This study takes the light timber construction wall structure as the research object. Based on the Helmholtz resonance principle, the structure design of the wall unit, impedance tube experiment and COMSOL MULTIPHYSICS simulation calculation were carried out to obtain the change rule of acoustic performance of the Helmholtz resonance wall unit structure. The research results show that the overall stability of sound insulation of the… More > Graphic Abstract

Yiping Sun^1,2, Jiadui Chen¹, Qiang Bai¹, Xuefeng Zhao¹, Meng Tao^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.3, pp. 1693-1716, 2022, DOI:10.32604/cmes.2022.019336

Abstract Research on the acoustic performance of an anechoic coating composed of cavities in a viscoelastic material has recently become an area of great interest. Traditional forward research methods are unable to manipulate sound waves accurately and effectively, are difficult to analyse, have time-consuming solution processes, and have large optimization search spaces. To address these issues, this paper proposes a deep learning-based inverse research method to efficiently invert the material parameters of Alberich-type sound absorption coatings and rapidly predict their acoustic performance. First, an autoencoder (AE) model is pretrained to reconstruct the viscoelastic material parameters of an Alberich-type sound absorption coating,… More >

Wei Chen^1,2, Zhaofeng Guo^3,4,*, Hongda Feng^3,4, Sheng Hu^1,2, Ling Lu^1,2, Chuanmin Chen^3,4, Xiaowen Wu^1,2, Hao Cao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 481-496, 2022, DOI:10.32604/fdmp.2022.015746

Abstract This study investigates a dual-cavity resonant composite sound-absorbing structure based on a micro-perforated plate. Using the COMSOL impedance tube model, the effects of various structural parameters on sound absorption and sound insulation performances are analyzed. Results show that the aperture of the micro-perforated plate has the greatest influence on the sound absorption coefficient; the smaller the aperture, the greater is this coefficient. The thickness of the resonance plate has the most significant influence on the sound insulation and resonance frequency; the greater the thickness, the wider the frequency domain in which sound insulation is obtained. In addition, the effect of… More >

Mohammad Javad Jafari¹, Mohsen Niknam Sharak², Ali Khavanin³, Touraj Ebadzadeh⁴, Mahmood Fazlali⁵, Rohollah Fallah Madvari^6,*

Sound & Vibration, Vol.55, No.2, pp. 117-130, 2021, DOI:10.32604/sv.2021.09729

Abstract Fabricating of metal foams with desired morphological parameters including pore size, porosity and pore opening is possible now using sintering technology. Thus, if it is possible to determine the morphology of metal foam to absorb sound at a given frequency, and then fabricate it through sintering, it is expected to have optimized metal foams for the best sound absorption. Theoretical sound absorption models such as Lu model describe the relationship between morphological parameters and the sound absorption coefficient. In this study, the Lu model was used to optimize the morphological parameters of Aluminum metal foam for the best sound absorption… More >

Jie Wang, Fuhang Jiang, Wenchang Zhao, Haibo Chen^*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 645-681, 2021, DOI:10.32604/cmes.2021.015894

Abstract A combined shape and topology optimization algorithm based on isogeometric boundary element method for 3D acoustics is developed in this study. The key treatment involves using adjoint variable method in shape sensitivity analysis with respect to non-uniform rational basis splines control points, and in topology sensitivity analysis with respect to the artificial densities of sound absorption material. OpenMP tool in Fortran code is adopted to improve the efficiency of analysis. To consider the features and efficiencies of the two types of optimization methods, this study adopts a combined iteration scheme for the optimization process to investigate the simultaneous change of… More >

Yipu Wang¹, Yonghua Wang^1,2,*, Zheming Liu¹, Huadong Yu¹, Jinkai Xu¹

Journal of Renewable Materials, Vol.9, No.5, pp. 923-941, 2021, DOI:10.32604/jrm.2021.014138

Abstract Noise pollution is one of the contemporary environmental pollution, which seriously damages people’s green and healthy life. In order to further improve the low frequency sound absorption performance of microperforated panel (MPP), a new plastocene coupled microperforated plate (PCMPP) is proposed. The acoustic properties of PCMPP with different apertures and perforation ratio were measured by transfer function method and compared with that of conventional MPPs. It is found that when the aperture was 0.8 mm, the peak value of sound absorption coefficient of PCMPP decreased by 150 Hz compared with MPP. In a certain range, PCMPP with larger apertures showed… More >

Mohamed Abd-Elbasseer^*, Hatem Kh Mohamed

Sound & Vibration, Vol.55, No.1, pp. 43-55, 2021, DOI:10.32604/sv.2021.09417

Abstract This research presents a thorough evaluation of the reverberation room at Acoustics Laboratory in National Institute of Standards (NIS) according to the related international standards. The evaluation aims at examining the room performance and exploring its effectiveness in the frequency range from 125 Hz to 10000 Hz according to the international standard requirements. The room, which was designed and built several years ago, is an irregular rectangular shape free from diffusers. Its volume is about 158.84 m³, which meets the requirement of the ISO 354 standard L_max < 1.9V^1/3. Cut-off frequencies of one and one-third octave are 63 Hz and… More >

Roohalah Hajizadeh¹, Ali Khavanin^2,*, Mohammad Barmar³, Ahmad Jonidi Jafari⁴, Somayeh Farhang Dehghan⁵

Sound & Vibration, Vol.53, No.5, pp. 207-222, 2019, DOI:10.32604/sv.2019.06523

Abstract Polyurethane foam as the most well-known absorbent materials has a suitable absorption coefficient only within a limited frequency range. The aim of this study was to improve the sound absorption coefficient of flexible polyurethane (PU) foam within the range of various frequencies using clay nanoparticles, polyacrylonitrile nanofibers, and polyvinylidene fluoride nanofibers. The response surface method was used to determine the effect of addition of nanofi- bers of PAN and PVDF, addition of clay nanoparticles, absorbent thickness, and air gap on the sound absorption coefficient of flexible polyurethane foam (PU) across different frequency ranges. The absorption coefficient of the samples was… More >