Experimental Sound Absorption of Several Loose Uncooked Granular Materials
Ayoub Boaubel1, Said Bousshine2, Mohammed Garoum3, Adil Ammar4
1Ayoub Bouble*, Mohammed V University in Rabat, Materials, Energy and Acoustics TEAM, Morocco.
2Said Bousshine, Mohammed V University in Rabat, Materials, Energy and Acoustics TEAM, Morocco.
3Mohammed Garoum, Mohammed V University in Rabat, Materials, Energy and Acoustics TEAM, Morocco.
4Adil Ammar Mohammed V University in Rabat, Materials, Energy and Acoustics TEAM, Morocco.
Manuscript received on October 12, 2019. | Revised Manuscript received on 22 October, 2019. | Manuscript published on November 10, 2019. | PP: 4578-4583 | Volume-9 Issue-1, November 2019. | Retrieval Number: A5237119119/2019©BEIESP | DOI: 10.35940/ijitee.A5237.119119
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Absorbent materials it’s an acoustic solution that can be used to control the reverberation time (RT) in deferent spaces as: conference rooms, in halls, theaters, cinema…. and also, it can be used in walls or ceilings of buildings to improve the acoustic insulation Which can be used for internal separations between spaces. This study focuses on the experimental study of the acoustic absorption coefficient of several granular food materials as a function of frequency 50 to 1600 Hz. All acoustic absorption tests performed in this study are performed by an acoustic impedance tube or Kundt tube. And to the knowledge of the author it is the first time in the literature that someone studies the acoustic behavior of this kind of materials. Several parameters were studied such as the effect of thickness on the sound absorption coefficient of the materials tested, like the influence of the grain form on the acoustic absorption by the introduction of a new parameter L / D, and finally the influence of density and type of material on the sound absorption coefficient. The objective of this work is to study the influence of the grain shape on the sound absorption coefficient, and that’s why we have chosen these fifteen materials each one with its own shape. The results of these experimental tests show that when the sample thickness rises, the acoustic absorption coefficient rises too with a shift from resonance frequency to low frequencies. When the L/D parameter rises, the absorption behavior increases too in all frequencies mentioned. Finally, as the density of the tested material rises, the percentage of sound absorption of the materials also rises.
Keywords: Acoustic Absorption Coefficient, Granular Materials, Granular Pastas, Impedance Tube
Scope of the Article: Materials Engineering