中文摘要：

针对一个非受限强旋流CH4/空气贫预混燃烧器的冷态工况和燃烧工况进行大涡模拟，建立了基于两步简化机理的改进代数二阶矩燃烧模型，模拟得到与实验数据相符的结果．为了进一步分析化学反应对湍流流动的影响，应用了空间关联函数和湍流能谱分析方法处理模拟结果，模拟结果显示燃烧增强了湍流涡团的能量．

英文摘要：

An unconfined swirling methane/air premixed flame was investigated using large eddy simulation(LES)in this study.With the modified algebraic second order moment model and two step reduced reactionmechanism,the simulation was performed,and the results were in good agreement with the experimentalones.To further study the effect of the reaction on turbulent flow,the spatial correlation function and energy spectrumanalysis were applied.The results show that the influence of combustion on turbulent flow is remarkable