1999 Fiscal Year Final Research Report Summary
Study on Gas-Liquid Two-Phase Flow in a Capillary Tube under Microgravity
| Project/Area Number |
10650178
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | The University of Tokushima |
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Principal Investigator |
OUSAKA Akiharu The University of Tokushima, Faculty of Engineering, Professor, 工学部, 教授 (70035806)
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| Co-Investigator(Kenkyū-buntansha) |
KUSANO Koji The University of Tokushima, Faculty of Engineering, Research Associate, 工学部, 助手 (50284310)
KARIYASAKI Akira The University of Fukuoka, Faculty of Engineering, Professor, 工学部, 教授 (10078652)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Multiphase Flow / Microgravity / Oil-Water Mixture Fluids / Horizontal Capillary Tube / Flow Pattern Map / Pressure Drop / Oil Plug Behavior / Multiresolution Analysis |
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| Research Abstract |
Experimental investigation was made on the flow pattern, the hold-up of oil, the frictional pressure drop and the behavior of oil bubble of a nearly-equal-density oil-water two-phase flow in a horizontal capillary tube to make clear the effects of tube diameter, viscosity and mixing method on them. The tube diameters examined are 5 mm and 2 mm, and the viscosities are 48.3 mPas and 0.82 mPas. The results are summarized as follows.
1. Flow pattern map was influenced by capillary tube diameter, viscosity and mixing method. The standard deviation, skewness and kurtosis of the probability density function of time-varying hold-up of oil depended on flow configuration.
2. Chisholm's correlation applicable for viscous-viscous flow in the gas-liquid two-phase flow agrees with the present experimental data. Consequently we can calculate the fictional pressure drop of a nearly equal density oil-water two-phase flow in a horizontal capillary tube.
3. The behavior of oil plug, such as oil plug length
… More
, velocity and passing frequency, in equal density oil-water flow was fundamentally different from that in air-water two-phase flow in a capillary tube.
(1) The velocity of oil bubble increases with the total volumetric flux, the correlation for non-slip agrees with the data in low total volumetric flux region. The value of distribution parameter in a nearly equal density oil-water two-phase flow changes gradually from 1.0 to 1.2 with increasing the total volumetric flux.
(2) The influence of four kinds of nozzle hole size on the inner tube in the mixing chamber and that of two types of mixing method were investigated. As a result, it was clarified that the nozzle hole size effected on the oil plug length but not the oil bubble velocity.
(3) From the multi-resolution analysis about the signals of hold-up and pressure drop, it was clarified that there was a oscillation between the nose of oil plug and the tail which showed the interfacial small waves between the nose of oil plug and the tail.
(4) The pipe inclination influenced on the two-phase flow multiplier of frictional pressure drop, but not affected very much on the hold-up. The two-phase flow multiplier of frictional pressure drop in vertical upflow was smaller than that in horizontal flow. Less
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