Effect of pressure oscillation on the shape of tiny bubble and mass transfer from the bubble
| Project/Area Number |
17K06152
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
Shuichi Iwata 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (00293738)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
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| Keywords | 非ニュートン流 / 粘弾性流体 / 流動複屈折 / 気泡 / 物質移動 |
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| Outline of Final Research Achievements |
We studied gas absorption rate around a bubble in viscoelastic fluid under pressure-oscillating field. The laser-induced fluorescence technique was applied to fluid around the tiny CO2 bubble under pressure-oscillating field. pH distribution around the bubble was visualized, which corresponds to rate of CO2 mass transfer. The absorption rate under pressure-oscillating field was enhanced by the local flow structure of negative wake in the vicinity of tiny bubble in the case shear-thinning. In addition, unsteady-state non-Newtonian finite element analysis was performed, in which the shape of the air-liquid interface can be determined by the force balance equation, considering inertia and the gravitational term. It was found that the alternative local flows near the bubble surface generated by pressure-oscillation give rise to lowered apparent viscosity for shear-thinning fluid, and enhancing the bubble rising velocity especially during contraction phase, as well.
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| Academic Significance and Societal Importance of the Research Achievements |
2色蛍光レーザー誘起法により気泡界面近傍の溶存CO2ガス濃度分布を可視化し，気泡界面近傍に存在する薄膜状の濃度境界層を明確化し、圧力振動場によってCO2吸収液が選択的に下部に排出される局所流動構造を示した。また、非ニュートン流動解析により、圧力振動場における定量的評価を行った。
液体中への気体の吸収操作は、化学プラントの反応器やCO2吸収プロセス等、産業界で広く用いられている。取り扱う流体が高粘性である場合にはSchmidt数が大きな値となるために、物質移動速度を改善する方法が望まれている。本研究の成果は、気泡界面近傍に存在する境界層を圧力振動の印加により操作できることを示している。
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Report
(4 results)
Research Products
(22 results)
