高压下湍流火焰速度测量与拟合

Measurement and Correlation of Turbulent Burning Velocity Under High Pressure

利用连续燃烧本生灯结合OH-PLIF火焰结构激光诊断技术获得了高压下预混湍流火焰瞬时前锋面图像,通过图像处理,得到了高压下多种混合气的湍流火焰速度及其拟合关系式。结果表明：高压预混湍流火焰前锋面为高度褶皱凹凸结构,现象上表现为大尺度的凸向未燃气的凸结构和小尺度的凸向已燃气的凹结构。合成气火焰比CH_4/air更加褶皱,前锋面更加精细。本文所有实验点高压湍流火焰速度可以拟合为S_T/S_L与[（P/P_0）（u′/S_L）]^n的形式,n约为0.4左右,表明湍流涡与火焰面的相互作用遵循自相似的规律。

Instantaneous flame front image of turbulent premixed flame under high pressure was obtained with Bunsen burner using OH-PLIF technique.Turbulent burning velocity of various mixtures and its correlation were derived from image processing.Results showed that turbulent premixed flame front structure was highly wrinkled,which was interpreted by the phenomenon that the large scale of convex structure which convex to the unburned gas superimposed with small scale of concave structure.The flame front of syngas was more wrinkled and fine compare to that of CH_4/air flames.The turbulent burning velocity under all the conditions at high pressure of this study could be correlated in the form of S_T/S_L and[（P/P_0）（u′/S_L）]^n,in which n is about 0.4 indicating that the flame-turbulence interaction is self-similar.