2004 Fiscal Year Final Research Report Summary
Structure and Dynamic Behavior of Flamelet with Strain as Turbulent Combustion Elementary Process
| Project/Area Number |
15360111
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Osaka University |
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Principal Investigator |
KOMIYAMA Masaharu Osaka University, Mechanophysics Engineering, Assistant Professor, 大学院・工学研究科, 講師 (40178372)
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| Co-Investigator(Kenkyū-buntansha) |
KINOSHITA Shinich Osaka University, Mechanophysics Engineering, Research Associate, 大学院・工学研究科, 助手 (70263209)
TAKEISHI Kenichirou Osaka University, Mechanophysics Engineering, Professor, 大学院・工学研究科, 教授 (70379113)
TAKAGI Toshimi Osaka Sangyo University, Mechanical Engineering, Guest Professor, 工学部, 客員教授 (40029096)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Flamelet / Dynamic behavior / Extinction / Stretch Rate / Preferential Diffusion / Unsteadiness / Direct Numerical Simulation / Laser Diagnostics |
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| Research Abstract |
The turbulent flame consists of the flamelet that receive the strain, and it is useful to clarify the structure and the dynamic behavior of the flamelet for understanding the structure and characteristics of turbulent flame, and establishing a reasonable analytical technique. Therefore, this research aims by an experiment and a direct numerical analysis to clarify flame structure, the extinction characteristics under the control of the flame strain, the structure and dynamic behavior of the edge flame caused by local extinction, which is related to the positive and negative flame strain rate, curvature effect, preferential diffusion, unsteadiness and locality of strain rate.
(1)By the numerical analysis that considers elementary chemical reaction and multi-component diffusion of the opposing-flow laminar diffusion flame that uses hydrogen and the methane as a fuel, the strain rate and the flow are controlled by changing the opposing flow velocity and by injecting a jet locally, the rela
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tion among extinction, the strain rate, and the flow fields was analyzed.
(2)The flow velocity fluctuation by the sound excitation was given to the fuel or air for the normal diffusion flame and the inverse-diffusion flame of a central jet flow, the flame with a large-scale vortex was formed, and the interacting behavior of the vortex and the flame was analyzed by two dimensional measurement of the temperature and the OH concentration profiles by the Rayleigh scattering and the laser-induced fluorescence.
(3)The influence was computationally analyzed, which the interaction between a flame and a vortex gives on flame structure and extinction. When the fluctuation of fuel velocity relatively is weak and the flame does not result in extinction, the preferential diffusion between species and the Lewis-number effect give a large influence on the temperature characteristic of the flame. When the velocity fluctuation is large, the heat release rate decreases with the process of the chemical non-equilibrium, and it results in extinction. Less
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