2010 Fiscal Year Final Research Report
Study on mass transfer process and turbulence structure in open-channel flows with wind-induced water waves
| Project/Area Number |
21760385
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Hydraulic engineering
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| Research Institution | Kyoto University |
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Principal Investigator |
SANJOU Michio Kyoto University, 工学研究科, 准教授 (80362458)
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| Project Period (FY) |
2009 – 2010
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| Keywords | 風波現象 / マルチカメラ・ステレオPIV / 乱流計測 / 組織乱流構造 / 3次元構造 |
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| Research Abstract |
When wind appears over the free-surface flows such as actual rivers and artificial channels, a significant velocity shear and water waves are generated near the air/water interface. It is inferred that coherent turbulence structure such as hairpin vortex in the near-wall region is also influenced by these interfacial fluctuations. However, a lot of uncertainties remain about the wind effects on wall-turbulence structure. In the first stage of the present study, PIV measurements were conducted in open-channel flows under the wind flows in order to reveal the effects of interfacial free-surface condition on coherent turbulence structure and energy transfer process in the inner and outer layers. Wind-induced water waves observed in natural lakes and ocean cause secondary currents called as Langmuir circulation. In the second stage, all three velocity components could be measured simultaneously by the stereoscopic PIV technique. The present multi-camera system allowed us to investigate the phase relation between the surface fluctuation and the velocity components, effects of aspect ratio on formation properties of Langmuir circulation and so on.
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