Development of measuring void fraction distribution and two-dimensional velocity fields of gas-liquid two-phase flow in liquid-metal using ultrasonic techniques
| Project/Area Number |
17KK0115
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| Research Category |
Fund for the Promotion of Joint International Research (Fostering Joint International Research)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Fluid engineering
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| Research Institution | Kobe University |
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Principal Investigator |
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| Project Period (FY) |
2018 – 2022
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥15,210,000 (Direct Cost: ¥11,700,000、Indirect Cost: ¥3,510,000)
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| Keywords | 液体金属 / 気泡 / ボイド分布 / 速度分布 / 超音波トモグラフィ / 超音波パルスドップラ法 / 流体計測 / 超音波 / 気泡鎖 / 二相流 |
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| Outline of Final Research Achievements |
To clarify the transient changes in two-phase flow in opaque liquid metal, measurement methods for void distribution and velocity distributions by using ultrasonic tomography and pulse Doppler methods were developed. Using the system, the bubbles' behavior and rising velocity of single chain bubbles at a constant bubble generation frequency in a gallium alloy were investigated. The test section was a pipe with an inner diameter of 50 mm, and the volume-equivalent bubble diameter was about 8.5 mm. The effects of bubble generation frequency and the horizontal magnetic field strength on the flow behavior were evaluated. Bubbles ascended with oscillation motion without a magnetic field. However, the oscillation motion was suppressed under the influence of the magnetic field resulting in the concentration of the bubble's passage position at the measurement cross-section. Furthermore, the bubbles' rising velocity changed with the magnetic field strength.
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| Academic Significance and Societal Importance of the Research Achievements |
高発熱密度の冷却において、液体金属の利用は有効な手段の一つである。しかしながら流体が不透明であることから、液体金属中の二相流動の実験的評価は多くの課題がある。本研究では、液体金属中において気泡分布と速度情報を取得可能な超音波計測技術を確立した。さらに、これらの手法が磁場を印加した条件においても有効であることを示した。これにより、気液密度比や表面張力が従来の流体と大きく異なる液体金属において、気泡の合体や分裂、さらには磁場印加による影響といった複雑な二相流の解明に貢献し、安全解析に必要とされる構成方程式の精度向上に寄与するものである。
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Report
(6 results)
Research Products
(20 results)
