Numerical analyses of suppression of sound emission by interference between a pair of helicalmodes in a supersonic jet
| Project/Area Number |
24560189
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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 |
Fluid engineering
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| Research Institution | University of Toyama |
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Principal Investigator |
WATANABE Daisuke 富山大学, 大学院理工学研究部(工学), 講師 (70363033)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2013: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2012: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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| Keywords | 超音速ジェット / マッハ波 / 空力騒音 / 線形安定性解析 / DNS / CFD / 乱流 / 騒音 |
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| Outline of Final Research Achievements |
The numerical results provide new physical features of the Mach wave generated in supersonic round jets, which lead to extinction of the Mach wave by introducing disturbance condition. Upstream disturbance conditions play an important role for the emission of the Mach wave in supersonic jets. The pressure fluctuations generated by the growth of the opposite helical mode are shown to be linearly superimposed into the jet near sound field. The numerical results indicate that the jet forced with a pair of first helical modes can indicate the elimination of Mach waves at restricted emission azimuthal angles due to the interference of these modes. The partial elimination of the Mach wave also appears in a turbulent jet at the frequency of the artificially forced an optimal combination of the helical modes at the inlet region. This forcing technique will be extended to the Mach wave reduction in the distinct azimuthal direction.
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Report
(4 results)
Research Products
(10 results)
