2014 Fiscal Year Final Research Report
Study on ultra lean combustion using swirl stagnation flow burners
| Project/Area Number |
24560220
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | University of Tsukuba |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 超希薄燃焼 / 予混合燃焼 / 旋回流 / 再循環領域 / 拡散熱的不均衡 |
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| Outline of Final Research Achievements |
In recent studies it was found that backflow of burned gas enables ultralean premixed combustion. In this study, we developed four swirl flow burners that can form a stable recirculation zone and a counterflow of burned gas and unburned gas, i.e., a bugle-shaped burner, a frustum-shaped burner with a flame holder, a sudden expansion burner, and a frustum-shaped burner without a holder, and tried to realize ultralean premixed combustion by using them. As a result, we succeeded in realizing almost steady ultralean combustion for both of methane-air and hydrogen-air in the three burner cases other than the bugle-shaped burner. It was found that in all the three cases larger Swirl number flow generally makes leaner combustion possible. Furthermore, a detailed-kinetics numerical simulation revealed that in a hydrogen-air flame there occurs a very strong combustion point at the leading edge of the flame due to so-called thermal-diffusive imbalance that is one of the Lewis number effects.
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| Free Research Field |
燃焼学
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