| Project/Area Number |
08405017
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 Tokyo |
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Principal Investigator |
KOBAYASHI Toshio Center for Collaborative Research University of Tokyo, Professor, 国際・産学共同研究センター, 教授 (50013206)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAGI Shu Faculty of Engineering, University of Tokyo, Lecturer, 工学部, 講師 (30272371)
OSHIMA Mari Institute of Industrial Science, University of Tokyo, Lecturer, 生産技術研究所, 講師 (40242127)
SAGA Tetsuo Institute of Industrial Science, University of Tokyo, Research Assistant, 生産技術研究所, 助手 (30013220)
TANIGUCHI Nobuyuki Institute of Industrial Science, University of Tokyo, Associate Professor, 生産技術研究所, 助教授 (10217135)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Multiphase flow / Numerical model / Large eddy simulation / Turbulence / Bubbly flow / Particle-laden flow / Bubble motion / Visualization |
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| Research Abstract |
An aim of this research was to develop models for a large eddy simulation (LES) of multiphase turbulence flow with dispersed particles and to evaluate and optimize them using numerical simulation. For modeling of multiphase flows, a direct numerical simulation (DNS) of bubble motions evaluated their effects on the fluid flow and the interaction between bubbles. Turbulence variation by small solid particles was also investigated. For evaluating a formulation of particle motions in the LES, a Lagrangian equation and a statistical averaged equation were compared by the numerical examinations. The numerical method of LES was developed based on the former model. These results were validated in views of the particles and the fluid flows using data of DNS and experiment with visualization techniques. For some basic flows, as mixing layers, jets, channel flows, the above models and the methods were examined in the range from laminar to turbulence, to indicate an universal information for the bubbly flow and the particle-laden air flow as follows,
a) Particle size effects on the bubble motions by the buoyancy forces and the turbulence could be analyzed by the LES including the precise model of the bubble motion and its contribution to the volume averaged equation.
b) The turbulence dissipation by the solid dispersed particles could be evaluated by a subgrid-scale model including the particle-fluid interaction, while a grid-scale interaction was not simulated by the present model effectively enough.
These results validated the feasibility of LES to the dispersed-particle multiphase flows and indicated that the temporal and the spatial scales of the turbulence and the particle motion should be considered for the modeling of the particle-fluid interaction and its optimization.
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