2013 Fiscal Year Final Research Report
Numerical analysis on flue instruments based on aerodynamic sound theory
| Project/Area Number |
23540455
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
TAKAHASHI Kin'ya 九州工業大学, 大学院情報工学研究院, 教授 (70188001)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAMI Toshiya 九州大学, 情報基盤研究開発センター, 准教授 (10270472)
KOBAYASHI Taizo 九州大学, 情報基盤研究開発センター, 学術研究員 (20467880)
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| Co-Investigator(Renkei-kenkyūsha) |
AOYAGI Mutsumi 九州大学, 情報基盤研究開発センター, 教授 (00260026)
NISHIDA Akira 九州大学, 情報基盤研究開発センター, 学術研究員 (60302808)
KOBAYASHI Hiromichi 慶応大学, 法学部, 教授 (60317336)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 流体音 / エアリード楽器 / 移動境界問題 / エッジトーン / 渦音理論 |
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| Research Abstract |
We study the interaction between the fluid field and the acoustic field in a small flue-instrument model based on Howe's energy corollary theory, which allows us to estimate the energy transfer from the acoustic field to the fluid field and vice versa. We develop a numerical method to implement the calculation of Howe's energy corollary. As a result, we find out which area near the mouth opening mainly contributes to the generation of sound: the aerodynamic sound is generated from the oscillating jet rather than vortices shed at the edge. Our result is essentially the same as the previous experimental result by Yoshikawa et al. and provides a numerical evidence to Howe's theoretical prediction. We further calculate Lighthill's sound source with the incompressible approximation and with full-compressible calculation. We find qualitative and quantitative differences between the two calculations. It indicates that the incompressible approximation usually used is insufficient.
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