Experimental investigation of correlation between cellular structure of the flame front and pressure

The present work experimentally studies the correlation between the cellular structure of a flame front and the pressure of methane/hydrogen/air laminar premixed flame at various equivalence ratios and hydrogen fractions in a spherical combustion chamber. The effects of the equivalence ratio and the hydrogen fraction on the explosion characteristics and evolution of the cellular structure of the flame front of methane/hydrogen/air were determined, and the correlation between cellular structure and pressure was analyzed. The results show that with an increase in the equivalence ratio or the hydrogen fraction, the pmax and its time increase monotonously. The mean area of all cells reaches a constant value, which tends to increase with an increase in the hydrogen fraction or the equivalence ratio. The absolute value of growth rate decreases with an increase in the equivalence ratio under 70% hydrogen fraction or with an increase in the added amount of hydrogen. The influence of pressure on the cellular structure decreases in the early stage after the flame edge reaches the quartz window under a certain equivalence ratio. When the flame develops to a certain degree, the influence of pressure on the cellular structure is limited.