| Project/Area Number |
62550152
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Osaka University |
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Principal Investigator |
KAJI Masuo Osaka University, Faculty of Engineering, Department of Mechanical Engineering, Associate Professor., 工学部, 助教授 (90029306)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Tadayoshi Osaka University, Faculty of Engineering, Department of Mechanical Engineering,, 工学部, 教務員
TAKEISHI Masayuki Osaka University, Faculty of Engineering, Department of Mechanical Engineering,, 工学部, 助手 (80150499)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Gas-Liquid Two-Phase Flow / Convective Heat Transfer / Evaporating Flow / Steam Generator / Frictional Pressure Drop / Turbulence Model / Optical Fiber Probe / Void Fraction / 熱伝達 / 乱流熱伝達 / 液滴エントレインメント / 圧力損失 / 沸騰二相流 / 液滴エントレイン / 乱流熱伝達理論 |
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| Research Abstract |
(1) OBJECTIVE : This study is concerned with the heat transfer characteristics of two-phase flow in evaporating tubes. The analogy between momentum and heat transfer is well established for single-phase flow. To predict the heat transfer coefficient in steam generators, application of the analogy between momentum and heat transfer for two-phase flow was proposed. The Validity of the analogy was investigated by experiments for air-water, steam-water and other two-phase systems.
(2)APPROACH : The following three experimental projects were conducted. Based on the experimental data, numerical calculation was carried out. 1. Heat transfer coefficient, pressure drop and void fraction were simultaneously measured. From the analogy the heat transfer coefficient was correlated with the two-phase multiplier of frictional pressure loss by using the void fraction. The validity of this correlation was clarified in annular flow region. 2. To measure void fraction of evaporating flow of refrigerant, multiple optical fiber probe was developed. Profiles of void fraction in a cross section were measured for various flow regime. 3. Convective boiling heat transfer characteristics were investigated by experiment for steam-water flow. In high quality region where nucleate boiling was suppressed, proposed relationship of the analogy was valid. 4. Numerical calculation was carried out for two-phase annular flow by using a turbulence model for single-phase flow. Agreement between experiments and calculation was fairly well for velocity profiles of air-water flow. As for the heat transfer coefficient of boiling flow satisfactory results were not obtained.
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