| Project/Area Number |
09650188
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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 | Osaka University |
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Principal Investigator |
TANAKA Toshitsugu Osaka University, Graduate School of Engineering, Assoc.Professor, 大学院・工学研究科, 助教授 (90171777)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUCHI Toshihiro Osaka University, Graduate School of Engineering, Research Assoc., 大学院・工学研究科, 助手 (80234045)
TSUJI Yutaka Osaka University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (10029233)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Multiphase Flow / Gas-Solid Flow / Turbulence / Numerical simulation / Meso-Scale Structure / cluster |
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| Research Abstract |
1. LBS of downward gas-solid flows in a vertical channel
Numerical smuations with two-way couping were performed for downward particle laden tutbulent flows in a verticul channel, of which conditions corrspond to those by a group of Stanford University.Fluid motion was culculated by using LES with the same models as in single phase flows and the motin of individual particles by the Lagrangian method.Particle-particle collisin was taken into considertion.
First, the effect of grid resolution of LES on the particle diffusion was investigated by appling filtering to gas-flow fields.The effect of grid resolution was correlated with Stokes number defined by the ratio of particle's relaxation time to the interaction time between a fluid eddy and a particle.An criterion of grid resolution of LES for particle motion was proposed.
Subsequently, LES of gas-solid flows was performed for three kinds of particles used in the corresponding experiment.The present simulations with two-way coupling predicted that particles tend to concentrate to high-speed streaks in the near-wall region, while the previous ones with one-way coupling predicted the contrary tendency.The predicted patterns of particle clauds in the channel-center region agree well with the experiment.
2. Structure of paticle cluster
The structure of particle cluster in a two-dimensional circulation fluidized bed is also simulated numerically.The simulation taking account of the chanel walls predicted smaller claster size than that without the effect of the chanel walls.It was found that the effect of particle size distribution on the scale of clusters is small.
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