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利用激光层析技术和数字图像处理技术对对冲方式下湍流预混火焰的结构及熄火特性进行了试验研究。采用 PIV方法测量了冷态对冲面附近的速度场 ,获得了速度应变率作为衡量流场对锋面燃烧影响的参数。在不同射流工况配置下 (Reynolds数 ,全局应变率 ,燃料的化学混合当量 ,不对称动量 ) ,观察到随着湍流对冲强度的提高 ,在高度皱褶的火焰锋面上存在非连续突触和空洞 ,这是局部熄火的表现 ,这些局部熄火点影响的扩展会导致火焰的整体熄火。此观点通过局部火焰锋面曲率的概率统计分析得到支持。另外 ,获得的在火焰熄火的极限条件 ,对实际燃烧器的设计有指导意义。
The structure and flameout characteristics of turbulent premixed flame under hedge mode were studied by laser tomography and digital image processing. The PIV method was used to measure the velocity field near the cold surface and the velocity strain rate was obtained as a parameter to measure the influence of the flow field on the frontal combustion. Under different jet conditions (Reynolds number, global strain rate, chemical compound equivalence of fuel and asymmetric momentum), it is observed that with the increase of turbulence intensity, there are discontinuous synapses on highly wrinkled flame front and Empty, this is the performance of partial flameout, the expansion of these partial flameout point will lead to the overall flame out. This view is supported by the statistical analysis of the probability of local flame front curvature. In addition, the ultimate flame extinguishing conditions obtained are instructive for the design of the actual burner.