1998 Fiscal Year Final Research Report Summary
Vortical structure and turbulence control in rotating fluids
| Project/Area Number |
08650080
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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 |
Engineering fundamentals
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| Research Institution | Okayama University |
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Principal Investigator |
YANASE Shinichiro Okayama University, Faculty of Engineering, Professor, 工学部, 教授 (20135958)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAMI Toshihiro Okayama University of Science, Faculty of Engineering, Professor, 工学部, 教授 (40144886)
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| Project Period (FY) |
1996 – 1998
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| Keywords | turbulence / control / uniform rotation / Coriolis force / vortical structure / cyclonic vortex / vortex layer / shear flow |
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| Research Abstract |
First the results obtained by the head investigator are described. Three papers have been published. Two of them are on the bifurcation phenomena in the flow through a curved duct, where the competitive effect of the Coriolis force and the centrifugal force associated with the duct curvature is studied. It is found that when these effect are balanced, the flow flux is maximum. The other is on the vortical structure in the rotating fluids. In DNS without mean shear flow, it is found that the resonant interaction plays an important role in the two-dimensionalization process of turbulence. In the simulations with mean shear flow, it is found that a coherent structure develops when the background absolute vorticity is zero. Next the results obtained by the sub-investigator are described, By the experimental investigation of turbulent curved pipe flow, it is found that the injection of swirling flow at the inlet of the pipe reduces the drag appreciably, which will contribute industrial application.
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