Measuring the free field acoustic impedance and absorption coefficient of sound absorbing materials with a combined particle velocity-pressure sensor

2006 ◽  
Vol 119 (5) ◽  
pp. 2826-2831 ◽  
Author(s):  
R. Lanoye ◽  
G. Vermeir ◽  
W. Lauriks ◽  
R. Kruse ◽  
V. Mellert
Keyword(s):  
Absorption Coefficient ◽  
Particle Velocity ◽  
Pressure Sensor ◽  
Acoustic Impedance ◽  
Free Field ◽  
Absorbing Materials ◽  
Velocity Pressure

Comparison of three measurement techniques for the normal absorption coefficient of sound absorbing materials in the free field

2009 ◽  
Vol 126 (6) ◽  
pp. 3020-3027 ◽  
Author(s):  
Kunikazu Hirosawa ◽  
Kazuhiro Takashima ◽  
Hiroshi Nakagawa ◽  
Makoto Kon ◽  
Aki Yamamoto ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Measurement Techniques ◽  
Free Field ◽  
Absorbing Materials ◽  
Normal Absorption

Investigating the Effects of Fibrous Material Compression on the Acoustical Behavior of Absorption and Barrier Materials

2006 ◽  
Vol 129 (2) ◽  
pp. 133-140 ◽  
Author(s):  
A. R. Ohadi ◽  
M. Moghaddami
Keyword(s):  
Absorption Coefficient ◽  
Fibrous Material ◽  
Transmission Loss ◽  
Element Model ◽  
Physical Parameters ◽  
Fibrous Materials ◽  
Barrier Materials ◽  
Rigid Frame ◽  
Absorbing Materials ◽  
The Galerkin Method

This paper discusses the effects of compression on acoustical performance of fibrous materials. A finite element model is used to predict the absorption coefficient and transmission loss of absorbing and barrier materials. This model is developed based on the Galerkin method and includes the equation of wave propagation in rigid frame porous material. The compression of fibrous material is entered to the model with relations that explain modifications of physical properties used in the wave equation. Acoustical behavior of absorption and barrier materials with and without compression is studied. It is shown that compression of the material leads to reduction of the transmission loss of the barrier materials and absorption coefficient of absorbing materials. In this regard, “thickness reduction” and “variations of physical parameters” due to compression are investigated.

scholarly journals A dynamic calibration method of free-field pressure sensor based on Hopkinson bar

AIP Advances ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 075223
Author(s):  
Wen Liang ◽  
Rong Chen ◽  
Yuwu Zhang
Keyword(s):  
Pressure Sensor ◽  
Free Field ◽  
Hopkinson Bar ◽  
Calibration Method ◽  
Dynamic Calibration ◽  
Dynamic Calibration Method

Utilization of Treated Red Meranti Wood Dust as Polymer Foam Composite for Acoustic Study

2013 ◽  
Vol 594-595 ◽  
pp. 760-764 ◽  
Author(s):  
Shafizah Sa'adon ◽  
Anika Zafiah M. Rus
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Sound Absorption Coefficient ◽  
Wood Dust ◽  
Polymer Foam ◽  
Tube Test ◽  
Acoustic Study ◽  
Foam Composite ◽  
Absorbing Materials ◽  
Scanning Electron

A Red Meranti Wood Dust (RMD) act as a filler for polymer foam composite has been investigated and proved to have ability to absorb sound. In this study, treatment of wood dust with and without acid hydrolysis named as WDB and WDA respectively was use as filler. This study was developed to compare the ability of sound absorption based on treated filler and particle size of wood dust. By choosing the size of 355 μm, three different percentage has been selected which is 10%, 15% and 20% for both conditions. These samples has been tested by using Impedance Tube test according to ASTM E-1050 for sound absorption coefficient, α measurement and Scanning Electron Microscopy (SEM) for determine the porosity for each samples. 10% loaded of WDB as filler gives highest sound absorption coefficient of 0.999 at 4015.63 Hz. Meanwhile for 20% loaded of WDA gives 0.997 at 3228.13 Hz. When comparing the sound absorption coefficient for both sounds absorbing materials, WDB-polymer foam composite RMD showed higher value of sound absorption coefficient, α at higher frequency as compared to WDA-polymer foam composite.

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