A fundamental study on the estimation of fluxes in boundary layers of rotating fluids by laboratory experiments
Project/Area Number |
17K05653
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Meteorology/Physical oceanography/Hydrology
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Research Institution | The University of Tokyo |
Principal Investigator |
Iga Keita 東京大学, 大気海洋研究所, 准教授 (60292059)
|
Project Period (FY) |
2017-04-01 – 2020-03-31
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Project Status |
Completed (Fiscal Year 2019)
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Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
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Keywords | 渦の室内実験 / 渦運動に伴う境界層 / 境界層内の運動量輸送 / 層流境界層・乱流境界層 / 円筒容器内の流れ / 軸対称渦 / 非軸対称な渦 / 流体 / 気象学 / 海洋物理 |
Outline of Final Research Achievements |
In a cylindrical container filled with water driven by a rapidly rotating bottom disk, a vortex motion is formed in a laboratory experiment. Considering the angular momentum exchange through the boundary layers, and comparing the theoretical calculation and the experimental results, the flow features of the boundary layers are investigated. The detailed measurements of the change of the surface elevation indicate that the momentum exchange between the fluid and the bottom or side-wall boundaries is proportional to the velocity difference, which indicates that the flow in the boundary layer is laminar. On the other hand, the flow at the free surface has also turbulent features; both laminar and turbulent boundary layers are formed in the same system with the same surrounding flow parameter.
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Academic Significance and Societal Importance of the Research Achievements |
室内実験によって境界層の性質を解析し、そこを通して行われる運動量輸送の評価を行ったが、室内実験の測定結果を通じて、境界層の素過程の性質を示すことができた。これは、地球流体の数値計算を行う際に必要となるパラメタリゼーションが数値実験を通して行われることが多い中、スケール間相互作用を測定できる室内実験の手法を用いた輸送量評価となっており、数値計算で用いるパラメタリゼーションの根拠づけとしての役割も果たす。
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Report
(4 results)
Research Products
(13 results)