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对空气气氛中甲烷/氧气反扩散火焰的形态和推举滞后特性进行了实验研究.实验中通过改变气体流量考察了气速变化对火焰形态演变及滞后特性的影响,并利用紫外相机系统研究了气速对不同形态火焰中OH*分布的影响.研究结果表明:甲烷气速、氧气气速和火焰的历史状态是决定火焰形态的三个重要参数,并以此对实验范围内的火焰形态进行了分区;氧气气速对不同形态反扩散火焰轴线上的OH*分布有相似的影响,当氧气缺乏时,反扩散反应区较短,当氧气富余时,反扩散反应区在轴向分布较广;同轴甲烷的气速对反扩散火焰的滞后特性影响显著,随着甲烷气速的增加,反扩散火焰的推举速度和再附着速度呈线性减小,部分预混火焰向反扩散火焰转变的速度呈线性增加.
In the experiment, the influence of the change of gas velocity on the morphological evolution and the hysteresis of the flame was investigated by changing the gas flow rate, and the effects of the gas velocity on the flame evolution and the hysteresis characteristics were also studied. Speed on the distribution of OH * in different forms of flame.The results show that the methane gas velocity, the oxygen gas velocity and the flame history are the three important parameters that determine the flame morphology, and thus the flame morphology in the experimental range Oxygen gas velocity has a similar effect on the distribution of OH * on the axes of different forms of anti-diffusion flame. In the absence of oxygen, the counter-diffusion reaction zone is short. When the oxygen is abundant, the reaction zone is widely distributed in the axial direction. The velocity of coaxial methane has a significant effect on the hysteresis characteristics of the anti-diffusion flame. With the increase of methane gas velocity, the pushing speed and the reattachment velocity of the anti-diffusion flame decrease linearly, and the velocity of some premixed flame to reverse diffusion flame A linear increase.