Frosting characteristic measurement and defrosting performance improvement
| Project/Area Number |
17F17365
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 外国 |
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| Research Field |
Thermal engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
党 超鋲 東京大学, 大学院新領域創成科学研究科, 准教授 (30401227)
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| Co-Investigator(Kenkyū-buntansha) |
SONG MENGJIE 東京大学, 新領域創成科学研究科, 外国人特別研究員
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| Project Period (FY) |
2017-11-10 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2019: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2018: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2017: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Heterogeneous nucleation / droplet solidification / freezing front / trapped air bubbles / temperature distribution / frost and ice / 着霜 / 除霜 / 白色干渉計 |
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| Outline of Annual Research Achievements |
As the prerequisite of frosting and icing, solidification of water droplets was firstly investigated in this project.A Hele-Shaw cell was designed and used to observe the solidification characteristics of two-dimensional water droplets. including heterogeneous nucleation, droplet morphology,freezing front evolution, trapped air bubbles, and temperature distribution inside a droplet, etc.
Air bubbles in frozen two-dimensional hydrophobic type water droplets were investigated in this year by quantitatively comparing the air releasing process from water droplets during freezing-melting cycles using pumped air distilled water and new made distilled water. Firstly, the subcooling degree would decrease as the dissolved air escaped from the bubbles in the melting stage. For new made distilled water droplet, the nucleation for three cycles did not occur until the experimental condition of the surface temperature was changed from -20 oC to -30 oC. Secondly, during the freezing-melting cycles, the air bubbles become smaller in dimension, and more in total number. Thirdly, the total escaped air volumes for two water droplets are obvious different due to different air dissolved content at start, while the total proportions for three cycles are similar, at 15.87% and 14.02% for two water droplets. Finally, the escaped air content, water droplet temperature decrease duration, and the subcooling degree for two water droplets surround with oil show the same fluctuation trend in the three freezing-melting cycles.
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| Research Progress Status |
令和元年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和元年度が最終年度であるため、記入しない。
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Report
(3 results)
Research Products
(9 results)
