Turbulent nonpremixed flames of methane near extinction: Mean structure from Raman measurements
Turbulent nonpremixed flames of methane near extinction: Mean structure from Raman measurements
复制标题
濒临灭绝的甲烷湍流非预混火焰：拉曼测量的平均结构
DOI：
10.1016/0010-2180(88)90062-4
复制
发表时间：
1988
影响因子：
4.4
通讯作者：
R. Dibble
中科院分区：
文献类型：
--
作者：
A. Masri;R. Bilger;R. Dibble
摘要对甲烷湍流非预混火焰中组分浓度-温度进行了自发Raman-Rayleigh测量。本文给出了温度、密度、混合物分数以及CH 4、O2、N2、H2O、H2、CO和CO2质量分数的波动均值和均方根值。平均拉曼-瑞利结果比较有利的探针测量的物种浓度和温度在类似的火焰。在一个给定的轴向位置，不反应（有限速率动力学），而不是不混合[高（″ 2）1 2]几乎完全解释了火焰结构的变化。随着火焰接近熄灭，CH 4和O2的Favre平均质量分数增加，而产物H2O、H2、CO和CO2的Favre平均质量分数减少。O2、H2O、H2、CO和CO2的温度和质量分数波动的均方根值也减小。虽然这些结果有利于扩散火焰结构的概念，但不能排除部分预混层流扩散火焰的存在。
Abstract Spontaneous Raman-Rayleigh measurements of species concentration-temperature have been made in turbulent nonpremixed flames of methane near extinction. The means and rms of fluctuations of temperature, density, mixture fraction, and the mass fractions of CH 4, O 2, N 2, H 2 O, H 2, CO, and CO 2 are presented in this paper. The mean Raman-Rayleigh results compare favorably with probe measurements of species concentrations and temperature made in similar flames. At a given axial location, unreactedness (finite rate kinetics) and not unmixedness [high (ξ ″2) 1 2] explains almost entirely the change in the flame structure. As the flame approaches extinction, the Favre averaged mass fractions of CH 4 and O 2 increase while those of the products H 2 O, H 2, CO, and CO 2 decrease. The rms of fluctuations in the temperature and mass fractions O 2, H 2 O, H 2, CO, and CO 2 decrease as well. Although these results favor the concept of a diffuse flame structure, the existence of partially premixed laminar diffusion flamelets cannot be excluded.