1987 Fiscal Year Final Research Report Summary
Oscillation of Thermal Interface in Hot Plenum of Fast Breeder Reactor
| Project/Area Number |
61460243
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Nuclear engineering
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
MADARAME Haruki The Faculty of Engineering, the University of Tokyo, 工学部, 助教授 (80092336)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Fast Breeder Reactor / Thermal Stratification / Fluid Vibration / Self-Induced Vibration / Entrainment / Buoyant Force / Hot Plenum / 温度成層界面 |
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| Research Abstract |
When a low temperature fluid flows into the bottom of a tank filled with a high temperature fluid, thermal stratification occurs because of differences in density. After a scram of a fast breeder reactor, the outlet temperature of the reactor coolant falls quickly, and a thermal interface appears in the hot plenum.
Oscillation of the interface was observed in thermal-hydraulic tests with water as a simulant coolant. The characteristics of the oscillation were examined, and an analytical model was proposed which explained the mechanism of the oscillation groth. The low density fluid was entrained by the high density fluid flow and was sucked down periodically. The buoyant force of the sucked fluid supplied energy to the oscillation if it is in phase with the upward movement of the oscillating interface. Therefore the oscillation grows in the case the high density fluid velocity is low in comparison with the oscillation period. The analytical results for the range of oscillation growth agreed well with the experimental results.
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