| Project/Area Number |
17K14594
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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 | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
Cerbus Rory 沖縄科学技術大学院大学, 流体力学ユニット, 研究員 (10795347)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
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| Keywords | 乱流遷移 / パイプ流 / 非平衡相転移 / 臨界指数 / 摩擦 |
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| Outline of Final Research Achievements |
When pipe flow transitions from the laminar to the turbulent state, packets of eddying flow called "puffs" and "slugs" invade the laminar flow. Although turbulence has long been understood to be different from this transitional regime, how these different puffs and slugs can act as mediators of the transition has not been investigated. In our research we showed in detail that puffs and slugs have the same quantitative structure as fully developed turbulence by looking at diagnostics such as friction and the universality of velocity fluctuation statistics. This result furnishes the necessary link between turbulence and its transition.
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| Academic Significance and Societal Importance of the Research Achievements |
The results obtained by our research efforts allow researchers to use the multitude of tools from high Reynolds number turbulence to study the transition. This is of practical use as well, since engineers now have the information necessary to predict energy costs for transitioning pipelines.
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