2016 Fiscal Year Final Research Report
On mechanism of large-scale flow reversals of turbulent flow in a confined domain
| Project/Area Number |
25400400
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2017-03-31
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| Keywords | 乱流理論 / 大規模流れ / 確率論的モデリング |
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| Outline of Final Research Achievements |
Some turbulent flows have coherence in a large spatial and temporal scale. In particular, turbulence in a confined container sometimes has a coherent circulating flow with the scale comparable to that of the container. Furthermore, under certain conditions, the orientation of this large-scale circulating flow changes suddenly after a long duration of one fixed orientation in an unpredictable manner. The subject of this research project is to understand mechanism of this reversal of the large-scale flow in turbulence.
Based on our precise numerical simulation of a two-dimensional turbulent system that is considered as one of the simplest systems showing the reversal, we developed a stochastic model. It describes well the random reversal of the two dimensional system. Through the analysis of the model, we showed that the reversal is caused by the random force added to the turbulent flow, the characteristic length-scale of the force and the viscosity.
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| Free Research Field |
流体物理学
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