Study of Ignition Delay Time of Methane Based on a Rapid Compression Machine

In order to investigate the combustion characteristics of methane( CH₄),effects of the driving gas pressure,initial pressure and equivalence ratio on the ignition delay time of CH₄/O₂/ Ar mixture were investigated using a rapid compression machine( RCM) at initial temperature 288 K,driving gas pressure of 0. 25- 0. 65 MPa,initial pressure of 0. 06- 0. 10 MPa and equivalence ratio of 0. 57- 1. 33 in this study. Kinetics model was built to simulate effects of the compressed temperature on the ignition delay time of CH₄/O₂/ Ar mixture and to simulate the combustion process with the same initial pressure and equivalence ratio as experiments. The results show that the ignition delay time of CH₄/O₂/ Ar mixture has a mild fluctuation within a narrow range under a certain range of driving gas pressure. The ignition delay time slightly extends under a high driving gas pressure. However,it has a significant increase when the driving gas pressure is extremely low. The ignition delay time of CH₄/O₂/ Ar mixture shortens with increasing compressed temperature. With increasing initial pressure,the ignition delay time of CH₄/O₂/Ar mixture shortens under different equivalence ratios,with increasing equivalence ratio,and the ignition delay time of CH₄/O₂/ Ar mixture extends under different initial pressures.