| Project/Area Number |
14550146
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Nagoya University |
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Principal Investigator |
WATANABE Takashi Nagoya University, Center for Information Media Studies, Professor, 情報メディア教育センター, 教授 (40182927)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASHITA Shintaro Gifu University, Faculty of Engineering, Professor, 工学部, 教授 (20023236)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Taylor Couette Flow / Rotating Disc / Bifurcation Phenomena / Initial Fluctuation of Flow / Transient Dynamics / Non-unique Flow / Complex Systems Science / Computational Fluid Dynamics / 端面効果 / 流動モード / 分岐現象 / 流体工学 |
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| Research Abstract |
Numerical studies were carried out on the flow, development and bifurcation phenomena in the flow between rotating cylinders. The flows around a rotating disc, as well as flows around circular cylinders, were investigated. In the case of the circular cylinders, we focused our attention on flows with free surface and initial fluctuations of velocity. The free surface model represented the effect of the surface tension in addition to the gravitational effect. The effect of the centrifugal force appears firstly at the free surface, and then the Ekman layer begins to develop on the stationary lower end wall. The final flow pattern, including the structure of the surface waves, showed good agreement with the experimental observation. In experiments, inevitable sources of physical errors appears. Considering these facts, we introduced quasi-isotropic flows in initial conditions and investigated their effects on flow developments. The intensity of the initial velocities~ were estimated by measuring the viscous scale. The numerical results showed that the final flow mode largely depended on the initial intensities and almost all the flow modes observed by experiments were predicted. In the study on flows around a rotating disc in a cylindrical enclosure, unstable flows in the gap between the rim of the disc and the inner wall of the enclosure were examined. It was shown that the unstable flow in the gap drastically changed the entire flow, and the bifurcation diagram with the increase in the Reynolds number was clarified.
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