2018 Fiscal Year Final Research Report
Creation of functional plates for control of two-phase flow and heat transfer, and development of an approach for control of near-wall bubble behavior
| Project/Area Number |
16K06119
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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 |
Thermal engineering
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
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| Research Collaborator |
Murai Yuichi
Denissenko Petr
Hagiwara Yoshimichi
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 対流熱伝達 / 気泡運動制御 / 機能表面 |
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| Outline of Final Research Achievements |
In this study, natural-convection two-phase flows and two-phase flows in microchannels have been investigated experimentally in order to develop an approach for controlling near-wall bubble behavior using functional plates. For the natural-convection two-phase flows, in the range of the width of hydrophobic region, WH, from 0 to 2 mm, the heat transfer coefficient increases by about 30% using the functional plate at WH=2 mm. This results mainly from an increase in the bubble concentration near the heated wall because of temporal attachment of bubbles at hydrophobic regions. For the two-phase flows in microchannels, in the range of the liquid flow rate from 100 to 400 micro l/min, bubbles can be intermittently generated from air-filled pockets only using air permeability of PDMS. In addition, the bubble generation frequency increases monotonically as the liquid flow rate increases.
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| Free Research Field |
熱工学
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| Academic Significance and Societal Importance of the Research Achievements |
学術的には，取得した実験データを利用することにより，マイクロバブルや大気泡気液二相流に関する数理モデルおよび数値計算手法の開発に貢献することができる．また，本研究で開発された壁面気泡挙動操作技術は，船舶などに対する気泡注入法の改善や気泡利用型熱流体デバイスの性能向上のための有効な手段として，機械・化学・船舶・医療などの幅広い分野での活用が期待されることから，地球環境問題の解決と低炭素社会の実現に大きく貢献することができる．
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