2020 Fiscal Year Annual Research Report
Exact coherent states in channel flow
| Project/Area Number |
18K03951
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| Research Institution | Kyushu University |
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Principal Investigator |
Wall Darren 九州大学, 工学研究院, 准教授 (30534309)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | Channel Flow / RPCF / transition / tilted vortex / tollmien-schichting |
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| Outline of Annual Research Achievements |
Channel Flow:
We have calculated a number of quaternary flows that bifurcate from the tertiary flows found last year. In contrast to the findings of Ehrenstein \& Koch ( JFM, 1991), so far none of these flows has been found to exist below the minimum value of Reynolds number (Re) at which two-dimensional flows can exist. A provisional conclusion is thus that Tollmien-Schlichting derived flows cannot participate in the first turbulent flows observed with increasing Re.
Rotating Plane Couette Flow:
Collaborating with M. Nagata and B. Song, an exact tilted vortex solution has been found that appears to correspond to the first flow observed upon loss of stability of the laminar flow. A periodic flow has also been identified that also participates in the early stages of transition.
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