N2O-C2H4预混气体火焰的传播特性

Flame Propagation Characteristics of Premixed N2O and C2H4

运用标准k-ε模型,对N 2O-C 2H 4预混气体在水平半封闭管道内火焰传播过程进行了数值模拟,得到了火焰锋面结构、传播速度、出口压力和燃烧区的气流速度随时间的变化规律。研究结果表明,管道内预混火焰传播过程分为3个阶段:点火初期的平面火焰传播阶段、Tulip火焰传播阶段和指形火焰传播阶段;火焰传播速度呈指数增长,管道出口处压力和气流速度均呈现出先增大后减小的趋势。同时,采用高速摄影系统、压力传感器、有机玻璃管等装置对预混气体的火焰加速进程和压力演变过程进行了验证,实验结果与数值模拟结果一致。

Flame propagation of premixed N 2O-C 2H 4 in a horizontal semi-closed tube was numerically simulated by using the standard k-εmodel.Time dependence of flame front structure,propagation velocity,outlet pressure,and flow speed in combustion zone was obtained.The results show that the process of premixed flame propagation in tube could be divided into three stages,which are plane flame propagation stage,tulip flame propagation stage and finger flame propagation stage.Flame acceleration presents the exponential trend,and pressure at the vent of the tube and flow speed of the premixed mixture first increase and then decline.At the same time,high speed photographic system,pressure sensor,and PMMA tube were used to study on the flame speed and pressure,which agree with the simulated results.