负压下CH4/空气层流预混火焰的自发辐射

摘要

The chemiluminescence of laminar premixed flame at low pressure was investigated by experimental and numerical simulation. A one-dimensional spontaneous emission model was established , in which OH(A) , CH(A)and C2(d)mechanism can be simulated simultaneously. The images of chemiluminescence of planar flame were taken. The peak intensity and peak concentration of excited species were picked up as major factors to study the chemiluminescence. The result shows that in the fuel lean and stoichiometry flame,OH(A) reaches the peak inten-sity first,followed by C2(d)and then by CH(A);in the fuel rich flame,the sequence turns to be OH(A)first,then CH(A)and finally C2(d). The peak intensity ratio of OH(A)/CH(A)and C2(d)/CH(A)is a monotonous function of equivalence ratio.%采用实验与数值模拟相结合的方法，对负压下甲烷空气层流预混火焰自发辐射进行了研究。由数值模拟建立起同时模拟OH(A)、CH(A)和C2(d)共3种激发态粒子自发辐射的一维模型，实验拍摄平面火焰自发辐射图像，提取激发态粒子峰值光强和峰值粒子数密度作为研究层流预混火焰自发辐射的主要参数。结果表明，当量比小于或等于1时，OH(A)最先达到峰值，C2(d)紧接着达到峰值，CH(A)最后达到峰值；当量比大于1时，OH(A)最先达到峰值，CH(A)紧接着达到峰值，C2(d)最后达到峰值；峰值比值 OH(A)/CH(A)和 C2(d)/CH(A)是当量比的单调函数。