Sound absorption of a porous material with a perforated facing at high sound pressure levels

2018 ◽  
Vol 425 ◽  
pp. 1-20 ◽  
Author(s):  
Feng Peng
Keyword(s):  
Porous Material ◽  
Sound Absorption ◽  
Sound Pressure ◽  
Sound Pressure Levels ◽  
High Sound

scholarly journals Sound absorption of porous metals at high sound pressure levels

2009 ◽  
Vol 126 (2) ◽  
pp. EL55-EL61 ◽  
Author(s):  
Xiaolin Wang ◽  
Feng Peng ◽  
Baojun Chang
Keyword(s):  
Sound Absorption ◽  
Sound Pressure ◽  
Porous Metals ◽  
Sound Pressure Levels ◽  
High Sound

scholarly journals Automotive traffic noise and urban public spaces

2021 ◽  
Vol 9 (72) ◽  
Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Urban Space ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Motor Vehicles ◽  
Open Spaces ◽  
Sound Levels ◽  
Measurement Results ◽  
Sound Pressure Levels ◽  
High Sound

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.

Sound absorption of a finite flexible micro-perforated panel absorber back by a rigid air cavity filled with a fibrous porous material

2021 ◽  
Vol 263 (3) ◽  
pp. 3625-3632
Author(s):  
Ho Yong Kim ◽  
Yeon June Kang
Keyword(s):  
Energy Dissipation ◽  
Porous Material ◽  
Fibrous Material ◽  
Alternative Energy ◽  
Sound Absorption ◽  
Sound Pressure ◽  
Absorption Coefficients ◽  
Air Cavity ◽  
Acoustic Cavity ◽  
Absorption Performance

Back by a rigid cavity filled with a layer of porous layer, the sound absorption performance of a micro-perforated panel (MPP) can be enhanced in comparison with other resonance based sound absorbers. In this paper, a theoretical model of a finite flexible MPP back by a rigid air cavity filled with a fibrous porous material is developed to predict normal sound absorption coefficients. Displacements of MPP and sound pressure field in fibrous porous material and acoustic cavity are expressed using a series of modal functions, and the sound absorption coefficients of MPP system are obtained. Additionally, comparison of energy dissipation by MPP and fibrous material is performed to identify effects of a fibrous material on the sound absorption of a MPP. As expected, at anti-resonance frequency of an MPP, the fibrous material provide an alternative energy dissipation mechanism.

scholarly journals Sound absorption of a micro-perforated plate backed by a porous material under high sound excitation: measurement and prediction

2013 ◽  
Vol 2 (4) ◽  
pp. 281 ◽  
Author(s):  
Rostand Boumda Tayong ◽  
Thomas Dupont ◽  
Philippe Leclaire
Keyword(s):  
Porous Material ◽  
Sound Absorption ◽  
Perforated Plate ◽  
Rigid Wall ◽  
Experimental Results ◽  
Mean Flow ◽  
Sound Levels ◽  
Specific Impedance ◽  
Air Flow Resistivity ◽  
High Sound

The sound absorption coefficient of perforated facings backed by porous materials is studied under high sound intensities in the absence of mean flow. The theoretical considerations are based on the equivalent fluid following the Johnson-Champoux-Allard approach and the use of the transfer matrix method. To take into account the high sound levels effects, the air flow resistivity of each layer is modified following the Forchheimer law. Two specimens of perforated plate are built and tested when backed by a polymeric foam and a fibrous material. A specific impedance tube setup is developed for the measurement of the surface acoustic impedance for sound pressure levels ranging from 90 dB to 150 dB at the surface of the perforated facing. To corroborate the validity of the presented method, two considerations are particularly depicted in the experimental results: first, the case where the perforated facing and the porous material are both directly backed by a rigid wall and the case where there is an air cavity between the porous material and the rigid wall. Good agreement is observed between the simulation and the experimental results.

Acoustic Resistance of an Orifice at High Sound Pressure Levels

2018 ◽  
Vol 64 (5) ◽  
pp. 563-566 ◽  
Author(s):  
A. I. Komkin ◽  
A. I. Bykov ◽  
M. A. Mironov
Keyword(s):  
Sound Pressure ◽  
Sound Pressure Levels ◽  
Acoustic Resistance ◽  
High Sound
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