微喷管氢气非预混射流火焰燃烧特性

摘要

采用考虑详细化学反应机理的数值计算，对空气伴流中微圆管氢气非预混射流火焰进行了研究。不同流速下火焰 OH 基元分布数值计算与实验结果吻合较好。结果表明：当微圆管内径保持不变时，随着燃料速度减小，火焰最高温度逐渐降低。当燃料速度接近熄灭极限速度时，火焰最高温度开始急剧下降；微圆管氢气非预混射流火焰存在最小流速对应的熄灭极限；随着管壁材料热导率降低，火焰中心轴线上的最高温度逐渐升高，喷口处壁面温度也升高；管壁材料热导率对火焰熄灭极限速度影响不显著。%Non-premixed hydrogen micro-jet flames in co-flow airs were studied by numerical computations with a detailed chemical reaction mechanism. The results of numerical computations agreed reasonably well with the counterparts of the experiments. The results showed that the computed maximum flame temperature decreased with decreasing fuel injection velocity for a fixed micro tube. When the fuel injection velocity was close to the minimum flow velocity sustaining a flame, the computed maximum flame temperature decreased sharply with decreasing fuel velocity. The wall materials had an influence on flame structures at a low fuel velocity. The lower the thermal conductivity of materials, the higher the wall temperature near the nozzle exit. The maximum flame temperature on the axis was relative higher. However, the effect of thermal conductivity on the quenching velocity of flame was not remarkable.