Detailed Analysis of the Flow in a Precessing Sphere and Spheroid
| Project/Area Number |
15K05219
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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 |
Kida Shigeo 同志社大学, 研究開発推進機構, 嘱託研究員 (70093234)
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 歳差 / 回転球 / 回転楕円体 / 安定性 / 不規則反転 / 臨界帯 |
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| Outline of Final Research Achievements |
The structure and stability of the steady flow in a precessing sphere and spheroid were studied by the linear stability theory, the asymptotic analysis and numerical simulation. For a sphere, the stability curve for the steady flow was determined over the whole range of the Poincare and the Reynolds numbers. The asymptotes of this curve agree excellently with the results of corresponding laboratory and numerical experiments. As for a spheroid, the structure of the steady flow was derived analytitcally in the large Reynolds number and small Poincare number limit for arbitrary values of the aspect ratio. The stability analysis of the steady flow showed the same power law as observed by laboratory experiments.
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| Academic Significance and Societal Importance of the Research Achievements |
最もシンプルな形状（球と楕円体）の容器の内部で最もシンプルな運動（２軸まわりの定角速度回転、すなわち歳差運動）によって駆動される流れは、閉領域系で実現する最も基本的で重要な非自明の流れ ― 流体力学の規準系 ― のひとつである。本研究は、その最も基本的な特性（定常流の構造と安定性）を明らかにしたもので、地球など回転する天体の内部構造や混合器、乱流発生装置などの研究に有用な基礎的知見を与えると期待している。
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Report
(5 results)
Research Products
(18 results)
