| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2015: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
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| Outline of Final Research Achievements |
The forced-feed and gravity-feed re-flooding experiments of a laboratory scale were conducted with a single and a parallel channel system, and phenomenological analysis was conducted. Boiling curves were estimated based on a rather simplified model, while sufficient for discussing dynamics during the quench. The estimated representative heat transfer coefficients in film and nucleate boiling process were nearly the same level of the conventional data presented in so-far published literatures. The cooling process of superheated high-temperature tubes is controlled mainly by the heat capacities of wall and water and the injected amount of water, and the formulated lumped-parameter model well represented the wall-temperature history during the re-flooding. In addition, in a parallel-channel system, flow oscillation between tubes, being so-called density wave oscillation, was observed. This oscillation deteriorates the cooling capability in film and transition boiling region.
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