1994 Fiscal Year Final Research Report Summary
Thermo-Hydraulics and Relaxation of Thermal Non-Equilibrium Two-Phase Flow
| Project/Area Number |
04452325
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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 | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
ARITOMI Masanori Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors Research Associate, 原子炉工学研究所, 助教授 (60101002)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Minoru Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors Associat, 原子炉工学研究所, 助手 (90171529)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Boiling two-phase flow / Thermo-hydraulics / Relaxation of superheated water / High conversion Light water reactors / Reflooding / Critical flow / Interfacial transport phenomena / Two-fluid model |
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| Research Abstract |
The purposes of this work are to offer a fundamental data base for next generation light water reactors and to sophisticate numerical codes for transient two-phase flow. The effect of channel gaps on thermo-hydraulics and the relaxation process of superheated water have been investigated experimentally and analytically. From the results, the following insights are clarified :
(1) For a channel gap narrower than 2mm, thermo-hydraulics of boiling two-phase flow is influenced by channels gaps, and new correlations of boiling heat transfer, two-phase friction multiplier.
(2) The drift flux model is applicable to analyze boiling two-phase flow in channels narrower than 2mm.
(3) During reflooding phase in channels narrower than 2mm, quench velocity becomes much lower than a reflooding rate, and pressure drop becomes so higher than that in channels wider than 2mm.
(4) Underpressure at the relaxation inception point of superheated water and time required for the relaxation inception can be evaluated by modified Jones'model.
(5) Macroscopic relaxation inception is governed by interfacial area density and integration of the superheating by the time passing through the superheated region.
(6) A new correlation of interfacial heat transfer is proposed and the two-fluid model including this correlation explains well the relaxation process and thermo-hydraulics of superheated water.
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Research Products
(8 results)
