Sound Absorption Properties of Al Foam

Author(s):  
Sang Youl Kim ◽  
Soo Han Park ◽  
Yong Su Um ◽  
Bo Young Hur
2014 ◽  
Vol 783-786 ◽  
pp. 1509-1512 ◽  
Author(s):  
Yun Jie Li ◽  
Yue Lu Ren ◽  
Zhen Dong Li ◽  
Fu Sheng Han

In the present study, needle like micro-Co3O4 rods were synthesized on the cell walls of open celled Al foam. The microstructure and phase composition of micro-rods and sound absorption properties of resultant samples were characterized. Compared with original Al foams, the modified ones showed enhanced sound absorption capacities, particularly at low frequencies, which were more obvious as the length of Co3O4 rods increased. The improvement is related to increased air flow resistance owing to increased roughness of the cell walls.


2005 ◽  
Vol 486-487 ◽  
pp. 468-471 ◽  
Author(s):  
Sang Youl Kim ◽  
Soo Han Park ◽  
Yong Su Um ◽  
Bo Young Hur

Aluminum foam with 0.2 g/cm3 density showed a good sound absorption property at frequencies higher than 2000 Hz. Compressed aluminum foam with an air gap of 50 mm or higher exhibited a very high sound absorption property near 400 Hz.


2021 ◽  
Vol 13 (2) ◽  
pp. 637
Author(s):  
Tomas Astrauskas ◽  
Tomas Januševičius ◽  
Raimondas Grubliauskas

Studies on recycled materials emerged during recent years. This paper investigates samples’ sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51).


2021 ◽  
Vol 283 ◽  
pp. 122654
Author(s):  
Mohd Zul Hanif Mahmud ◽  
Norhidayah Abdul Hassan ◽  
Mohd Rosli Hainin ◽  
Che Ros Ismail ◽  
Ramadhansyah Putra Jaya ◽  
...  

2021 ◽  
pp. 1-17
Author(s):  
Seyed Ehsan Samaei ◽  
Ebrahim Taban ◽  
Umberto Berardi ◽  
Seyyed Mohammad Mousavi ◽  
Mohammad Faridan ◽  
...  

Author(s):  
Nathapong Sukhawipat ◽  
Thanathach Yingshataporn-a-nan ◽  
Tanapat Minanandana ◽  
Kitchapat Puksuwan ◽  
Laksana Saengdee ◽  
...  

2017 ◽  
Vol 15 (3) ◽  
pp. 445-451 ◽  
Author(s):  
G. Thilagavathi ◽  
S. Neela Krishnan ◽  
N. Muthukumar ◽  
Santhana Krishnan

2013 ◽  
Vol 38 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Dariusz Pleban

Abstract Efficient ultrasonic noise reduction by using enclosures requires the knowledge of absorbing properties of materials in the frequency range above 4 kHz. However, standardized methods enable determination of absorption coefficients of materials in the frequency range up to 4 kHz. For this reason, it is proposed to carry out measurements of the sound absorption properties of materials in the free field by means of a tone-burst technique in the frequency range from 4 kHz to 40 kHz at angles of incidence varying from 0° to 60°. The absorption coefficient of a material is calculated from the reflection coefficient obtained by reflecting a tone-burst from both a perfectly reflecting panel and a combination of this panel and the sample of the tested material. The tests results show that mineral wool and polyurethane open-cell foam possess very good absorbing properties in this frequency range.


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