Characteristics of the premixed flame in a triple flame

Burning velocity and thermal diffusive structure of a triple flame generated with methane-air mixture were experimentally investigated in various fuel concentration gradients. The preheat zone width by their theory was larger than the measured thermal diffusive width of triple flame and was almost constant at any concentration gradients. Burning velocity along the premixed flame wing indicate the distribution of the flame temperature. These profiles and flame structure showed the tendency that heat flux from non-premixed flame to premixed flame goes up by increasing the concentration gradient. There existed the thermal interaction between the premixed and non-premixed flames at a leading edge of the triple flame. Non-premixed flame interacted with rich flame stronger than the lean premixed flame.