基于OH-PLIF技术的环形燃烧室预混火焰结构实验

针对微型燃气轮机环形燃烧室中的燃烧特性,利用平面激光诱导荧光(PLIF)技术,对环形燃烧室内甲烷/空气预混湍流多束火焰燃烧开展实验研究,得到OH自由基物质的量浓度分布,并研究雷诺数和当量比对火焰结构特征参数的影响。结果表明:OH自由基浓度分布呈现环形结构,并有火焰托举和分叉现象,OH-PLIF瞬时和平均图像揭示了火焰具有湍流和层流预混结构共同特征。火焰结构特征参数的定量分析表明,雷诺数升高,拉伸火焰预混锥形结构,促进射流之间相互作用；康达效应使内焰向内壁面弯曲,火焰张角增大；适当调节预混火焰的当量比,有利于火焰结构的稳定。 

Experiment on structure of premixed flame in annular combustor using OH-PLIF

In view of the combustion characteristics of a micro gas turbine annular combustor, a planar laser induced fluorescence (PLIF) technique was used to investigate the effects of Reynolds number and equivalent ratio on the structural parameters of a methane/air premixed turbulent flame in the annular combustor. Results showed that the OH radical concentration distribution exhibited a ring structure with flame lift and bifurcation phenomena. The instantaneous and average images of OH-PLIF revealed that the flame had the common characteristics of turbulent flow and laminar premixed structure. The quantitative analysis of the characteristic parameters of flame structure showed that when the Reynolds number increased, the flame premixed conical structure was stretched and the interaction between jets was promoted. The conda effect made the inner flame bend towards the inner wall and the flame angle increase. Proper adjustment of the equivalent ratio of premixed flame is beneficial to the stability of flame structure.