| Project/Area Number |
17560184
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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 |
Thermal engineering
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| Research Institution | Kyoto University |
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Principal Investigator |
KAWANABE Hiroshi Kyoto University, Department of Energy Conversion Science, Associate Professor, エネルギー科学研究科, 助教授 (60273471)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIYAMA Takuji Kyoto University, Department of Energy Conversion Science, Professor, エネルギー科学研究科, 教授 (30203037)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Turbulent Mixing / Large Eddy Simulation / Particle Image Velocimetry / Laser Induced Fluorescence / Non-homogeneity in Fuel-Air Mixture / Detailed Chemistry / Stochastic Model / Auto-ignition Process / ラージエディーシミュレーショ / 簡略化反応機構 |
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| Research Abstract |
In order to clarify formation process of the non-homogeneity in fuel-air mixture, and combustion process of this type of mixture, following three studies were mainly performed.
The flow and mixing process for high-speed unsteady jets are analyzed using computational fluid dynamics (CFD) included in heterogeneity of mixture concentration with stochastic approach. The results show that the time history of jet development is successfully agreed with experimental data for methane and hydrogen fuels. Furthermore, the time-development of micro-mixing process is successfully described with PDF model. Also, the difference of local heterogeneity between methane and hydrogen jets is discussed.
Distributions of velocity and concentration of turbulent gas jets with various densities from helium to carbon dioxide against ambient air are measured by using PIV and LIF methods. The turbulent transport of the jet fluid is directly investigated to analyzing the distributions of jet-fluid concentration and its vortex motion. The result shows that the self-similarity exists between profiles of scalar flux and Reynolds stress along the radial direction. Furthermore, several sub-grid scale scalar-flux models for large eddy simulation are discussed. Based on the scattering plots of model values of sub-grid scale scalar flux against the measured values, the characteristics of each model are basically similar for every density conditions.
An auto-ignition process of the non-homogeneous mixture was investigated using a numerical calculation based on the chemical kinetics and stochastic approach. The results show that the starting points of the low temperature oxidation and ignition delay period are hardly affected by the equivalence-ratio variation, however, the combustion duration increases with increasing variance of equivalence ratio. Furthermore, the combustion duration is mainly affected by the non-homogeneity at the ignition and not very much affected by the mixing rate.
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