Research on the relation of flame front curvature and oscillatory flame propagation by external laser irradiation method
Research on the relation of flame front curvature and oscillatory flame propagation by external laser irradiation method
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DOI：
10.1016/j.proci.2008.05.058
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
M. Tsuchimoto;O. Fujita;T. Honko;Y. Nakamura;Hiroyuki Ito
中科院分区：
文献类型：
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作者：
M. Tsuchimoto;O. Fujita;T. Honko;Y. Nakamura;Hiroyuki Ito
研究了外加CO2激光吸收引起的乙烯预混气体的振荡传输现象。在直径为50 mm、压力为0.1 Mpa的燃烧管中充入预混气体，沿燃烧管中心轴线照射不同直径的CO2激光。实验结果表明，火焰前沿曲率受辐照光束直径的控制，对振荡传播行为有很大影响。当光束直径较小时，火焰振荡现象明显，且随着火焰前锋曲率的增大，振荡频率变大。另一方面，当光束直径大于某一值时，不能观察到振荡现象。根据时间分辨观测发现，当火焰出现振荡传播时，火焰前锋曲率随时间波动，最大曲率出现的时刻对应于火焰传播减速或暂停的时刻。观测结果支持了前人提出的振荡传播机理，包括火焰前锋曲率与热扩散不稳定性的关系。
Oscillatory propagation phenomena of ethylene premixed gas induced by absorption of externally supplied CO2laser was investigated. Premixed gas was filled in a combustion tube of 50mm in diameter at 0.1MPa and CO2laser beam of different diameter was irradiated along the center axis of the tube. The experimental results showed that the flame front curvature was controlled by the irradiated beam diameter and had strong effect on the oscillatory propagation behavior. When the beam diameter is narrow, the flame oscillation phenomena clearly appeared and the oscillation frequency became larger with increased flame front curvature. On the other hand, oscillation phenomena could not be observed when beam diameter was lager than a certain value. According to the time-resolved observation, it was found that the flame front curvature fluctuated with time when oscillatory propagation appeared and the instant of the maximum curvature presence corresponded to the instant of flame propagation deceleration or pause. The observed results could support the mechanism of the oscillation propagation proposed in the previous study, which included the relation of the flame front curvature and thermal-diffusive instability.