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 - 16 December 2021

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. 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 - 21 April 2021

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… 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 - 20 February 2021

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,… 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… More >