Investigation of curvature statistics of turbulent premixed Bunsen flames based on leading points concept

In previous studies, it was showed that the leading point, namely, the positively curved flame front, may be vital in controlling the propagation of flame, thus controlling the burning intensity of turbulent premixed flames. This paper is aimed at investigating the morphologies of the leading points under low and relatively high turbulence intensities based on flame curvature statistics. Premixed C3H8/H2/air flames were obtained with a Bunsen burner. Flame front was captured with OH-PLIF technique. The results show prevalent leading points with positive curvatures at low turbulence intensity. Percentage of positive curvatures were observed to increase at lower turbulence intensity. However, with increasing turbulence intensity, such feature can be mitigated or even overpowered with equal probability of negative and positive curvatures. Proper models for leading point are recommended according to the experimental results. However, question remains as to the underlying mechanism of leading point concept.