Physical mechanisms to induce flow-transitions and to sustain turbulence
| Project/Area Number |
15K05220
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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 | Doshisha University |
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Principal Investigator |
Mizushima Jiro 同志社大学, 研究開発推進機構, 嘱託研究員 (70102027)
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| Project Period (FY) |
2015-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2015: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 流体 / 数理物理 / 計算物理 / 力学系 / 非線形物理 / 流体物理学 |
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| Outline of Final Research Achievements |
In the present research project, I have clarified physical mechanisms underlying instability and transitions of several major flows. The induction mechanisms of oscillatory thermal convection in two-component fluid and also in double-layered fluid were elucidated by evaluation of torques acting on the fluid. The appearance of a large-scale vortex, so-called 'bathtub vortex', in a rectangular vessel was found to be caused by pressure force exerted by the lateral walls. The flow through a channel with an expanded section was found to become oscillatory due to 'trapped instability’. The driving mechanism of Tollmien-Schlichting waves appearing in transition of the plane Poiseuille flow was found to be explained by mutual interactions between two flow fields defined by the real and imaginary parts of the eigen functions by analyzing the torques exerting on each flow field. From these investigations, I obtained many fruitful results and published or scientific papers to prominent journals.
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| Academic Significance and Societal Importance of the Research Achievements |
流れの安定性は自然科学だけでなく工学的にも重要であるが、不安定性が生じる機構についてはほとんど調べられてこなかった。本研究計画では流れの不安定性を渦の生成という観点から見直し、不安定性による新たな振動と流れパターンの発生に着目して、代表的な流れの不安定性発生機構を明らかにした。特に、平面ポワズイユ流の不安定機構の解明の手法は幅広い分野の流れに応用できるので、今後の乱流遷移の研究に重要な研究方法となると期待される。矩形断面容器中の大規模渦の発生機構の解明は「バスタブ渦の発生原理」として、広く中学生、高校生、教員だけでなく、一般の市民の興味を集め、台風や竜巻などへの興味を引き出すことができた。
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Report
(6 results)
Research Products
(25 results)
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[Book] 理工学のための数値計算法2019
Author(s)
水島 二郎、柳瀬眞一郎、石原 卓
Total Pages
255
Publisher
数理工学社;サイエンス社 (発売)
ISBN
9784864810616
Related Report
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[Book] 流体力学2017
Author(s)
水島二郎、柳瀬眞一郎、百武徹
Total Pages
231
Publisher
森北出版社
ISBN
9784627675711
Related Report
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