| Project/Area Number |
15560135
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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 | University of Fukui |
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Principal Investigator |
YAMAMOTO Fujio University of Fukui, School of Engineering, Professor, 大学院・工学研究科, 教授 (50020227)
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| Co-Investigator(Kenkyū-buntansha) |
MURAI Yuichi Hokkaido University, School of Engineering, 大学院・工学研究科, 助教授 (80273001)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Flow Visualization / Image Measurement / PIV / Multiphase Flows / Gas-Liquid Two-Phase Flows / PTV / Turbulent Shear Flows / PIV-CFD Hybrid System / 気液二相乱流 / 同時計測 / ポストプロセッシング / 乱流計測 / 実効粘性 |
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| Research Abstract |
The present research has been carried out to construct a system of PIV (Particle Image Velocimetry) as a parallel computing station, and has been applied to analyze turbulent structures in multiphase flows. As a result, the following remarks were concluded ;
A. Concerning construction of PIV parallel computing station :
A-1 After we developed a new hybrid system of PIV and CFD which was a combined system consisting numerical analysis technique for solving Navier Stokes equation and VGT (Velocity Gradient Tensor technique for PTV, it was confirmed that the hybrid system could compute the pressure field around a Savonius type of wind turbine.
A-2 Bubble-bubble interaction in bubbly flows were discussed with 3-D PTV. It was made clear that attractive forces were acted in the vertical direction and exclusive forces were acted in the horizontal direction.
A-3 A new inverse analysis has been devised and applied to bubbly flows at high void fraction, and then a new technique for computing liquid
… More
phase flow field from PIV/PTV measurement using the inverse analysis has been developed.
B. Concerning analysis of turbulent structure of gas-liquid two-phase flows :
B-1 A new system for synchronizing a high speed high resolution vide camera and a shear stress sensor was constructed, and the friction drag modification mechanisms in wall sliding bubbly flows were elucidated with PIV measurement results.
B-2 Effective viscosity, turbulent flow characteristics and additional viscosity were discussed in Taylor-Couette bubbly flows in a gap between coaxial double circular cylinders, and then the transition phenomenon from ring vortex to spiral vortex was visualized and discussed.
B-3 Reynolds stress distribution in boundary layers of gas-liquid two-phase flows close to the flat wall was measured using a new shallow focal PTV system, and consequently the relation between Reynolds stress and friction drag reduction in the boundary layer of the two-phase flow was discussed.
B-4 In order to elucidate the turbulent structures of bubbly flows and slug flows in a helical coil tube, a new CT image measurement system was developed. As a result, formation of secondary flows due to the centrifugal force effects on the two-phase flows and bubble distribution were newly found and discussed.
All the above results were published as 25 papers in the academic journals described in the references Less
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