| Project/Area Number |
06452176
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
MATSUO Kazuyasu Kyushu University, Graduate School of Engineering Sciences, Professor, 大学院・総合理工学研究科, 教授 (30037759)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAZATO Yoshiaki Kyushu University, Graduate School of Engineering Sciences, Research Associate, 大学院・総合理工学研究科, 助手 (30253537)
AOKI Toshiyuki Kyushu University, Graduate School of Engineering Sciences, Associate Professor, 大学院・総合理工学研究科, 助教授 (20150922)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥8,300,000 (Direct Cost: ¥8,300,000)
Fiscal Year 1996: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1994: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | Compressible fluid / Supersonic nozzle / Choking phenomenon / Flash evaporation / Micro-nozzle |
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| Research Abstract |
1. When intitially subcooled high temperature and high pressure liquid is accelerated through a converging-diverging nozzle and is expanded beyond its asturation condition, flash evaporation occurs in the converging section or at the throat of the nozzle. The choking of such a flow with flash evaporation is classified into three patterns.
2. The choking condition depends on the initial pressure and the subcooling of the compressible liquid. A flow model for calculating the critical massflux through the nozzle is presented assuming an isentropic, homogeneous, equilibrium two-phase flow. The mass flowrate calculated by the present model agrees well with the experimental results.
3. When the flow choked at the nozzle throat, a pressure wave is generated and propagated upstream so as to adjust the upstream flow conditions. The propagation velocity of a pressure wave through a compressible gas-liquid two phase flow depends on the void fraction and the relation between them is established.
4. The characteristics of supersonic micro-nozzle depends not only on the Mach number but also the Reynolds number based on the flow condition at the nozzle exit. The range of overexpansion, correct-expansion, and underexpansion of a such a nozzle is clarified, and the data of the critical flow rate through the supersonic micro-nozzle was obtained.
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