Experimental investigation on microstructure behavior of premixed methane-air flame-flow interaction in a semi-vented chamber

To explore the premixed methane-air flame microstructure behavior and the flame-flow interaction, the premixed methane/air flame was studied in a semi-vented chamber. A high speed camera and schlieren images methods were used to record the processes of interaction between rarefaction wave and flame. Meanwhile, a pressure sensor was utilized to catch the pressure variation in the process of flame propagation. The experiment results showed that the interference of rarefaction wave on flame caused the flame front structure change, which led to the flame transition from laminar to turbulent quickly. The rarefaction wave intervened in the flame by turning the flame front surface into dentiform structure. The violent turbulent combustion began to appear in part of the flame front and spreaded to the whole flame front surface. The rarefaction also decreased the flame propagation speed.