Experiments on dynamical motion of buoyancy-induced flame instability under different oxygen concentration in ambient gas
Experiments on dynamical motion of buoyancy-induced flame instability under different oxygen concentration in ambient gas
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DOI：
10.1016/j.expthermflusci.2008.05.005
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发表时间：
2008-09
影响因子：
3.2
通讯作者：
H. Gotoda;Shintaro Kawaguchi;Y. Saso
中科院分区：
文献类型：
--
作者：
H. Gotoda;Shintaro Kawaguchi;Y. Saso
实验研究了非预混火焰在不同环境氧浓度下浮力诱导火焰不稳定的动力学运动，重点研究了火焰尖端振荡频率和振幅随环境氧浓度的变化规律。火焰尖端振荡频率随环境气体氧浓度Xo的增加而单调增加，而火焰尖端振荡振幅随环境气体氧浓度Xo的增加而急剧减小。用Cetegen和Ahmed [B.M.]提出的理论方程可以清楚地解释不同氧浓度下振荡频率的变化Cetegen， T.A. Ahmed，浮力羽流和池火的周期性不稳定性实验，燃烧与火焰93(1993)157-184。随着Xo的增加，火焰尖端位置减小，燃烧产物与周围气体界面的周期性波动幅度变小。这导致在高氧浓度环境下火焰尖端振荡幅度的显著减小。
We experimentally investigated the dynamical motion of buoyancy-induced flame instability under different oxygen concentrations in ambient gas for a non-premixed flame, focusing on how the oscillation frequency and amplitude of the flame tip change with oxygen concentration in ambient gas. The oscillation frequency of flame tip ftincreases monotonically with increasing oxygen concentration in ambient gas Xo, while the oscillation amplitude at flame tip Amdrastically decreases with increasing Xo. The change in the oscillation frequency for different oxygen concentrations can be clearly explained by the use of the theoretical equation proposed by Cetegen and Ahmed [B.M. Cetegen, T.A. Ahmed, Experiments on the periodic instability of buoyant plumes and pool fires, Combustion and Flame 93 (1993) 157–184]. As the flame tip location decreases with increasing Xo, the magnitude of the periodic fluctuation of the interface between hot combustion products and ambient gas becomes small at the flame tip. This leads to a remarkable decrease in the oscillation amplitude of the flame tip in a high oxygen concentration environment.