Numerical analyses of suppression of sound emission by interference between a pair of helicalmodes in a supersonic jet

• Project/Area Number: 24560189
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: University of Toyama
• Principal Investigator: WATANABE Daisuke 富山大学, 大学院理工学研究部(工学), 講師 (70363033)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥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)
• 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

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.

Research Products

• [Journal Article] The effect of upstream disturbance on the angle of sound emission in a supersonic round jet (2014)
  • Author(s): Daisuke WATANABE, Hiroshi MAEKAWA
  • Journal Title: Journal of Fluid Science and Technology Volume: 9 Issue: 3 Pages: JFST0054-JFST0054
  • DOI: 10.1299/jfst.2014jfst0054
  • NAID: 130004695323
  • ISSN: 1880-5558
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] 超音速境界層の遷移における流入攪乱スペクトルの影響 (2014)
  • Author(s): 渡辺大輔, 前川 博
  • Organizer: 日本流体力学会年会2014
  • Place of Presentation: 東北大学 川内北キャンパス
  • Year and Date: 2014-09-15 – 2014-09-17
• [Presentation] 超音速円形ジェット音響場における流入攪乱の影響 (2014)
  • Author(s): 渡辺大輔, 前川 博
  • Organizer: 日本機械学会2014年度年次大会
  • Place of Presentation: 東京電機大学 東京千住キャンパス
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] ノズル後端からの撹乱を用いた圧縮性混合層の音響場 (2014)
  • Author(s): 伊東 和磨,渡辺大輔,川口 清司
  • Organizer: 日本機械学会北陸信越支部第51期総会・講演会
  • Place of Presentation: 富山県立大学
• [Presentation] 1. THE EFFECT OF UPSTREAM DISTURBANCE ON THE ANGLE OF SOUND EMISSION IN A SUPERSONIC ROUND JET (2013)
  • Author(s): Daisuke Watanabe, Hiroshi Maekawa
  • Organizer: 4th International Conference on Jets, Wakes and Separated Flows, ICJWSF2013
  • Place of Presentation: Nagoya Univ.
• [Presentation] 超音速円形ジェット音響場における流入攪乱の影響，日本機械学会2013年度年次大会講演論文集 (2013)
  • Author(s): 渡辺大輔,前川 博
  • Organizer: 日本流体力学会年会2013
  • Place of Presentation: 東京農工大学
• [Presentation] ヘリカルモードペアにより励起された超音速円形ジェットの渦構造 (2013)
  • Author(s): 渡辺大輔,前川 博
  • Organizer: 第91期 日本機械学会流体工学部門 講演会
  • Place of Presentation: 九州大学
• [Presentation] THE EFFECT OF UPSTREAM DISTURBANCE ON THE ANGLE OF SOUND EMISSION IN A SUPERSONIC ROUND JET (2013)
  • Author(s): Daisuke WATANABE
  • Organizer: 4th International Conference on Jets, Wakes and Separated Flows, ICJWSF2013
  • Place of Presentation: Nagoya, Japan
• [Presentation] 超音速円形ジェットにおける流入撹乱の音波放射角度への影響 (2012)
  • Author(s): 渡辺大輔
  • Organizer: 日本流体力学会年会2012
  • Place of Presentation: 高知大学朝倉キャンパス
• [Presentation] 超音速ジェットにおけるヘリカルモード組み合せの音響場に及ぼす影響 (2012)
  • Author(s): 渡辺大輔
  • Organizer: 日本機械学会流体工学部門講演会
  • Place of Presentation: 同志社大学 今出川キャンパス