Sound absorption mechanism of an aqueous solution in nonelectrolyte

1990 ◽  
Vol 92 (3) ◽  
pp. 1986-1993 ◽  
Author(s):  
Harumi Endo
Keyword(s):  
Aqueous Solution ◽  
Sound Absorption ◽  
Absorption Mechanism

Multiporous open-cell poly(vinyl formal) foams for sound absorption

RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7653-7660 ◽  
Author(s):  
Bai Xue ◽  
Jianguo Deng ◽  
Junhua Zhang
Keyword(s):  
Aqueous Solution ◽  
Vinyl Alcohol ◽  
Sound Absorption ◽  
Poly Vinyl Alcohol ◽  
Open Cell

A series of multiporous open-cell poly(vinyl formal) (PVF) foams were obtained by crosslinking poly(vinyl alcohol) (PVA) with different contents of formaldehyde in aqueous solution.

scholarly journals Ultrasonic Absorption Mechanism in an Aqueous Solution of Isopropyl Alcohol

1976 ◽  
Vol 49 (5) ◽  
pp. 1413-1414 ◽  
Author(s):  
Sadakatsu Nishikawa ◽  
Mitsuo Mashima ◽  
Tatsuya Yasunaga
Keyword(s):  
Aqueous Solution ◽  
Isopropyl Alcohol ◽  
Ultrasonic Absorption ◽  
Absorption Mechanism

New acoustical technology of sound absorption based on reverse horn

2016 ◽  
Vol 30 (34) ◽  
pp. 1650403 ◽  
Author(s):  
Yong Yan Zhang ◽  
Jiu Hui Wu ◽  
Song Hua Cao ◽  
Pei Cao ◽  
Zi Ting Zhao
Keyword(s):  
High Frequency ◽  
Sound Absorption ◽  
Mechanical Energy ◽  
Low Frequency ◽  
Acoustic Energy ◽  
Absorption Mechanism ◽  
Structure Changes ◽  
Potential Applications ◽  
Energy Focusing ◽  
The One

In this paper, a novel reverse horn’s sound-absorption mechanism and acoustic energy focusing mechanism for low-frequency broadband are presented. Due to the alternation of the reverse horn’s thickness, the amplitude of the acoustic pressure propagated in the structure changes, which results in growing energy focused in the edge and in the reverse horn’s tip when the characteristic length is equal to or less than a wavelength and the incident wave is compressed. There are two kinds of methods adopted to realize energy dissipation. On the one hand, sound-absorbing materials are added in incident direction in order to overcome the badness of the reverse horn’s absorption in high frequency and improve the overall high-frequency and low-frequency sound-absorption coefficients; on the other hand, adding mass and film in its tip could result in mechanical energy converting into heat energy due to the coupled vibration of mass and the film. Thus, the reverse horn with film in the tip could realize better sound absorption for low-frequency broadband. These excellent properties could have potential applications in the one-dimensional absorption wedge and for the control of acoustic wave.

scholarly journals Sound absorption mechanism of porous asphalt pavement.

1999 ◽  
Vol 20 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Michiyuki Yamaguchi ◽  
Hiroshi Nakagawa ◽  
Takuya Mizuno
Keyword(s):  
Sound Absorption ◽  
Asphalt Pavement ◽  
Absorption Mechanism ◽  
Porous Asphalt

Sound-Absorption Mechanism of Structures with Periodic Cavities

2021 ◽  
Author(s):  
Yingqin Luo ◽  
Jing-jun Lou ◽  
Yan-bing Zhang ◽  
Jing-ru Li
Keyword(s):  
Sound Absorption ◽  
Absorption Mechanism

scholarly journals Structural Design and Sound Absorption Properties of Nitrile Butadiene Rubber-Polyurethane Foam Composites with Stratified Structure

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 946 ◽  
Author(s):  
Xueliang Jiang ◽  
Zhijie Wang ◽  
Zhen Yang ◽  
Fuqing Zhang ◽  
Feng You ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Structural Design ◽  
Sandwich Structure ◽  
Sound Absorption ◽  
Low Frequency ◽  
Thickness Ratio ◽  
Butadiene Rubber ◽  
Absorption Mechanism ◽  
Nitrile Butadiene Rubber ◽  
Absorption Performance

Sound absorbing composites with stratified structures, including double-layer and sandwich structures, were prepared through the combination of nitrile butadiene rubber (NBR) and polyurethane foam (PUFM). The effects of the thickness ratio of layers, different stratified structures and the variety of fillers on the sound absorption performance of the NBR-PUFM composites and the sound absorption mechanism were studied. The results show that the NBR-PUFM composite with a sandwich structure and thickness ratio of 1:8:1 displays good sound absorption, which could be improved further by adding fillers. Because the airflow resistivity, resonance absorption, interface dissipation and interface reflection were combined organically in the sandwich structure, the composites show excellent low-frequency sound absorption performance. Moreover, the composite also has advantages in cost and functionalization aspects.

A Numerical Investigation on Sound Absorption Mechanism of Micro Resonator with Offset Slits

2015 ◽  
Vol 23 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Jun Xu ◽  
Xiaodong Li ◽  
Yueping Guo
Keyword(s):  
Numerical Simulations ◽  
Vortex Shedding ◽  
Sound Absorption ◽  
Numerical Data ◽  
Absorption Mechanism ◽  
Practical Applications ◽  
Acoustic Liners ◽  
Low Dissipation ◽  
Parametric Description ◽  
Micro Resonator

Acoustic liners are widely used in commercial aero-engine to suppress noise. In theoretical investigations, the liner geometry is often assumed as an array of symmetric micro resonator with orifice or slit at the center. However, in real application, orifices or slits distributed in micro resonator are offset. For better understanding of sound absorption mechanism of micro resonator with offset slits under high incident sound pressure level (SPL), direct numerical simulations (DNS) using high order low dispersion and low dissipation computational aeroacoustics (CAA) method are carried out. The simulations are first validated by experimental data, showing good agreement and establishing the relevance of the simulation methodology. Numerical simulations of resonators with single offset slit or two slits are then conducted. The two sound absorption mechanisms, namely viscous dissipation and vortex shedding, are discussed with detailed numerical data and analysis, which lead to quantitative parametric description of the energy partition between the two mechanisms as a function of both frequency and geometry. It is shown that offset slit can reduce vortex shedding and results in less sound absorption. The effects of more than one slit are, however, opposite; more vortex shedding occurs with more slits so that sound absorption is enhanced. This may potentially help guide liner design in practical applications.

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