Acoustic Absorption Characteristics of Perforated Thin Plate with Air Jets and Cavity
| Autor: | Reiji Tomiku, Hiromitsu Hamakawa, Eiichi Nishida, Kenta Asakura, Toru Otsuru, Hiroki Matsuoka, Eru Kurihara, Taiki Yamai, Hidechito Hayashi |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
business.industry Frequency band Internal pressure behavioral disciplines and activities Transfer function Volumetric flow rate Optics Attenuation coefficient otorhinolaryngologic diseases Tube (fluid conveyance) sense organs Sound pressure Acoustic impedance business psychological phenomena and processes |
| Zdroj: | Open Journal of Fluid Dynamics. :1-9 |
| ISSN: | 2165-3860 2165-3852 |
| Popis: | The present paper focuses on the effect of air jets through a perforated thin plate on the characteristics of an acoustic absorption coefficient. We measured the flow rate, internal pressure, acoustic pressure, and transfer function by using an improved acoustic impedance tube. The normal incidence absorption coefficient was calculated from the measured transfer function using transfer function methods. As a result, the frequency characteristics of the acoustic absorption coefficient against the frequency showed a maximum value at the local frequency. The peak frequency of the acoustic absorption coefficient depended on the thickness of the background air space and the thickness of the perforated plate. As the flow rate increased through the micropores, the peak level of the acoustic absorption coefficient also increased until a flow rate of 80 l /min. As the flow rate further increased, the peak level of the acoustic absorption coefficient decreased and that of the high frequency band increased. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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