2020 Fiscal Year Final Research Report
Research on Behavior Prediction of Cylindrical Line Structure with Rotation in Flow
Project/Area Number |
18H01634
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Review Section |
Basic Section 24020:Marine engineering-related
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Research Institution | The University of Tokyo |
Principal Investigator |
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Project Period (FY) |
2018-04-01 – 2021-03-31
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Keywords | 回転円柱 / 流体力 / 流速分布 / 付加質量 |
Outline of Final Research Achievements |
The characteristics of the fluid force acting on a rotating cylinder in the flow and the motion characteristics of the cylindrical line structure rotating in the flow were clarified. Drag decreases until the rotation ratio is around α = 1.2, and then increases. Lift increases to around α = 3. Then, along with drag and lift, the increase in value weakens from around α = 3. The flow velocity in the rotation direction can be made dimensionless by the surface velocity of the cylinder. In addition, the distance from the surface of the cylinder can be made dimensionless by the radius of the cylinder, which decreases logarithmically with respect to the radial direction. In the basin experiment using the flexible model, it was confirmed that the motion frequency of the model shifts to a lower frequency as the rotation speed increases. It is considered that rotation increases the additional mass of the model.
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Free Research Field |
海洋環境工学
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Academic Significance and Societal Importance of the Research Achievements |
流れ中で回転する円筒構造物の流体力及び運動特性が明らかになり、その原因が円柱周りの流れであることが明確になった。それにより、流れ中におかれた回転する円筒構造物の応力及び振動が予測可能となり、最適で安全なドリルパイプ運用に結びつく制御方法の可能性が見えてきた。また、回転による流れ中におかれる円筒構造物の揚力増加の大きさや回転速度との関係が明らかになったことで、回転により発生すると揚力を活用する新たな機構の構想につながることが期待できる。
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