2017 Fiscal Year Final Research Report
Development of high-time-resolution shear stress sensor for multi-phase flow and mechanism of drag reduction using the sensor
| Project/Area Number |
16K18006
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Fluid engineering
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| Research Institution | Muroran Institute of Technology |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2018-03-31
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| Keywords | 流体工学 / 乱流 / 抵抗低減 / せん断応力 / 気泡 |
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| Outline of Final Research Achievements |
We developed a novel shear stress meter using principle of laser Doppler velocimetry to examine different time scale effects in phenomena of frictional drag reduction by injecting bubbles into turbulent boundary layer. The realized sampling frequency of the stress meter is 500 kHz and is high enough to sense effects of individual passages of bubbles beneath a sensor in the stress meter. Applicability of the shear stress meter was examined in horizontal turbulent channel flows and the results showed good agreement with Dean’s curve of the friction coefficient for the turbulent channel flows even with a short measurement time, 4 s. The measurement also indicated measurable range of the stress meter determined by selection of a spring inside the meter. A preliminary test of the stress meter in bubbly flows under uncontrolled conditions of bubble injections provided reasonable results of friction coefficient.
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| Free Research Field |
流体工学
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