Fundamental study on combustion characteristics of diffusion flame focusing on spatial-temporal fluctuation scale of turbulence.
| Project/Area Number |
17K06181
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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 | Iwate University |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2017: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | 燃焼 / 拡散火炎 / 熱工学 |
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| Outline of Final Research Achievements |
A stretched cylindrical diffusion flame was used in which the local structure of the turbulent diffusion flame was modeled. The flow unsteadiness was modeled by sinusoidal oscillation of the oxidizer flow velocity. In order to contribute to the advancement of exhaust gas recirculation technology of diesel engine, CO2 and N2 contained in exhaust gas were used as diluents for fuel and oxidizer. The following results were obtained. As the fluctuation frequency of the oxidizer flow rate increases, the fluctuation amplitude of the velocity gradient of the fuel stream increases, and the fluctuation amplitude of the mass flux of the fuel flowing into the flame increases. The fluctuation amplitude of the flame luminosity, which is related to the combustion reaction, also increases as the frequency increases. The flame curvature effect of the flame diluted with CO2 appears more remarkably than the flame diluted with N2, and the fluctuation amplitude of flame luminosity appears larger.
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| Academic Significance and Societal Importance of the Research Achievements |
従来の燃料流と酸化剤流の速度を同位相で正弦波的に変動させたときの火炎の応答特性に関する研究では，速度の変動周波数が増加するにつれて，反応速度，火炎温度，発熱速度の変動振幅は単調に減少することが示されている．しかし，本研究のように酸化剤流の速度のみを正弦波的に変化させた場合，周波数の増加に対して，火炎輝度（反応の活発さ∝反応速度）の変動振幅が，速度の変化域における定常火炎のそれよりも大きくなるといった興味深い燃焼現象が見られ，考察することができた．さらに，火炎曲率の影響が希釈剤の種類によって異なることも示すことができたことは，学術的意義があり，エンジンを含む燃焼機器の開発においても意義がある．
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Report
(4 results)
Research Products
(4 results)
