| Project/Area Number |
01550177
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Osaka University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
NAKABE Kazuyoshi 大阪大学, 工学部, 助手 (80164268)
MIZUTANI Yukio 大阪大学, 工学部, 教授 (80028993)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Turbulent Combustion / Premixed Flame / Flame Propagation Limit / Lean Flammability Limit |
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| Research Abstract |
The high-load combustion is one of the recent interest in combustion technology in designing effective combustion facilities. The control of turbulent mixing and flame propagation are essencial to burn a large rate of fuel in a limited combustion space.
In the present project, we planned to elucidate the effects of turbulence on the propagation limit and the fine structure of premixed turbulent flames, and to apply the results to the control of the high-load combustion.
The following conclusions have been obtained.
1) With the increase in turbulence intensity, the fine structure of a turbulent flame changes itself from a chemistry-controlled laminar flamelet to a mixing-controlled distributed reaction zone. The structure of laminar flamelet disappear at the lean flame propagation limit when the mixture strength of the flame is decreased.
2) The flame of distributed reaction zone can be defined as a flame near extinction or a flame which lost the ability of self-propagation.
3) Initial turbulence in an approaching flow enhances the mixing and flame spread in a combustor. Initial intense turbulence is effective for the high-load combustion.
4) The initial turbulence does not contribute to the enhancement of combustion in a lean mixture near flammability limit. The excessive turbulence produces the structure of distributed reaction zone, hence the local extinction of flames.
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