1987 Fiscal Year Final Research Report Summary
Vortex Dynamica ans Sound Emission
| Project/Area Number |
60460042
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理学一般
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| Research Institution | Unicersity of Tokyo |
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Principal Investigator |
KAMBE Tsutomu Univ. Tokyo, Faculty of Science, Associate Professor, 理学部, 助教授 (60013679)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAZAKI Takeshi The National Institute for Environmental Studied, Researcher, 研究員 (50142097)
KIMURA Yoshifumi Univ. Tokyo, Faculty of Science, Research Associate, 理学部, 助手 (70169944)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Soud emission / Vortex sound / Vortex ring / Vortex sheet / 渦糸 |
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| Research Abstract |
Main aim of this research is to investigate basic aspects of vortex sound based on the experiment, and further to reveal its fundamental laws of the vortex motion and associated sound radiation by the analysis of the basic equations of fluid dynamics
In the experiment, a high speed vortex ring of about 50m/s is made in an anechoic chamber, and the sound generated by its collision with a cyinder is measured at various angular positions. The obeserved sound pressures are recorded automatically and averaged over several sets of data. The augular distribution of the acoustic pressure is expressed in terms of Fourier series. It is one of the remarkable results of the present project that multipole components of the obseved acoustic pressure have been found
In the first year (1985) of the present project, an anechoic chamber was constructed. This provided good experimental environment, and the experimental project started substantially. In the next year (1986), a system of precise acoustic measurement and a wave memory were furnished. This enabled exact measurement, and various properties of the detected signals were examined. In the final year (1987), a signal synthesizer, a printer and a text book were bought. This enabled good experimental test and recotd. The book has been useful for studying various fields of acoustics.
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