2013 Fiscal Year Final Research Report
Investigation of the supression of turbulent vortex formation and the frictional drag reduction effect on ship hull due to hydrogel painting
| Project/Area Number |
24760675
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Naval and maritime engineering
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| Research Institution | Osaka University |
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Principal Investigator |
TAKAGI Youhei 大阪大学, 基礎工学研究科, 助教 (40435772)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 乱流制御 / 水和型塗膜 / ハイドロゲル / 直接数値計算 / すべり速度 / 多孔質性 / 乱流渦 |
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| Research Abstract |
Hydrogel painting for ship hull makes hydration layer in sea water and has various functionalities. In this study, we revealed the effect of frictional drag reduction with hydrogel painting surface based on the relation with turbulent vortical structure formation. In experiment, we made a rotating annular cylinders apparatus with painted surface on the inner cylinder, and measured the torque acted on the inner cylinder. From experimental data, it was shown that the drag reduction effect of hydrogel painting became strong when the thickness of painting layer became small. In addition, we carried out the numerical simulations of channel flow with local slip velocity and penetration of fluid into wall, and found that the drag reduction effect depended on the scale of turbulent vortex structure and the thickness of boundary layer.
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