2016 Fiscal Year Final Research Report
Investigation of non-coalescence phenomenon between a liquid drop and a liquid surface by coupling molecular gas dynamics approach with computational fluid dynamics
| Project/Area Number |
26420102
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | 液滴 / マイクロ・ナノ気体流れ / 分子気体潤滑膜 / 分子気体力学 / 数値流体力学 |
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| Outline of Final Research Achievements |
When you drip coffee, you may often see one of the drops land on the surface and remain intact. This phenomenon can be seen between a drop and a surface of the same liquid, like water. It is a surprising fact that a drop and a surface of the same liquid do not coalesce immediately. This phenomenon is not only academically interesting but also industrially important. Although it has been investigated for more than a century, its mechanism is still unclear. The objective of the present study is to investigate its mechanism by reproducing this phenomenon in numerical simulations. We focused on the role of molecular gas film between the drop and the liquid surface, and clarified that when the drop is just about to land on the vibrating liquid surface, high pressure appears in the molecular gas film which prevents both liquid surfaces from contacting. It was also found that the drop bounces to the rhythm of the descent of liquid surface, so that the non-coalescence is maintained stably.
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| Free Research Field |
流体工学
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