| Project/Area Number |
15K05852
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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 | High Energy Accelerator Research Organization |
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Principal Investigator |
Okamura Takahiro 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 准教授 (90415042)
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2015: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | 超臨界ヘリウム / 乱流 / 直接数値計算 / 超電導 / 冷却技術 / 冷媒放出 / 放出シミュレーション / 自然対流 / DNS / GPGPU / GPU |
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| Outline of Final Research Achievements |
Flow field induced by heat input often shows unique characteristics such as thermal plume with sharp interface between hot domain and cold one, pseudo boiling and piston effect that heat propagates due to the adiabatic compression process. These phenomena are mainly induced due to the special behaviors of the thermo physical properties near critical point. In this study, we clarified the time and spatial evolution behaviors of the coherent structures formed by the velocity and temperature field from near the wall to the bulk. In addition, as an engineering application, we also developed simulation tool to predict the thermo-fluid behaviors of helium in the large scale systems that can not be verified from experiments. The numerical experiments were also performed on the helium convection diffusion behaviors when helium with the supercritical pressure was released to the atmosphere from large scale cryogenic equipment such as superconducting detector and accelerator.
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| Academic Significance and Societal Importance of the Research Achievements |
超臨界ヘリウムは主に素粒子実験等の比較的中規模から大規模超電導マグネットなどの冷却に使用される．ヘリウム３はもとよりヘリウム４も近年価格が高騰しており，インベントリ低減が必須となる．本研究で得られた知見は冷却流路形状などのシステム最適化を図るために適用することが出来ると考えている．またこうした大規模システムにおいて，こうした極低温のヘリウムが何らかの事象により装置外部へ放出された際の流動挙動から設備全体の安全に関する知見について，実験を実施することの困難さから十分に明らかにされているとは言えない．本研究ではこうした点においても知見を与えるものである．
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