Effect of L/D Ratio of Combustion Chamber on Premixed CH4-Air Flame Dynamic Behavior

Methane was widely used in many combustion systems. The premixed flame propagation in a chamber was a typical deflagration process. To explore the complicated gas deflagration mechanism in combustion system, it is necessary to discern flame propagation characteristics of gas fuel in a certain combustion chamber. Combustion dimension plays an important role in flame propagation behavior, therefore a model of different aspect (L/D) ratio chambers filled with premixed methane-air were performed to explore the flame propagation behavior. Based on numerical simulation results and theoretical analysis, the corresponding propagation characteristics such as pressure changes and temperature changes were obtained, which shows that the larger L/D Ratio of combustion chamber was, the greater flame speed and pressure, which mainly due to the less loss of heat and adiabatic compression of the high-temperature burnt gases.