2013 Fiscal Year Final Research Report
Frictional drag reduction mapping of multiphase flow
| Project/Area Number |
24860001
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| Research Category |
Grant-in-Aid for Research Activity Start-up
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Hokkaido University |
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Principal Investigator |
OISHI Yoshihiko 北海道大学, 工学(系)研究科(研究院), 助教 (90617078)
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| Project Period (FY) |
2012-08-31 – 2014-03-31
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| Keywords | 流体工学 / 省エネルギー / 乱流 / 摩擦抵抗低減 / 混相流 / 気泡 / 計測 |
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| Research Abstract |
The following 3 articles are achieved.
In this study, quantification of turbulence events and bubble behavior are provided by the development of Time - y-axis imaging analysis based on behavior of individual particle and bubble. The turbulence event and bubble are summarized into three points. (1) Frictional drag characteristics in turbulent horizontal channel bubbly flow by using shear stress sensor. (2) Wall shear stress fluctuations indicate that the bubble injection produces quasi-random fluctuations that eliminate positive spikes on the fluctuations in turbulent flows. This elimination takes primary role on the drag reduction in the present case that the bubble deformations are allowed. (3) Frictional drag characteristic of single bubble and clustering bubble are clarified. Drag reduction map is renewed including clustering bubbles
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