Laminar Burning Speeds and Flammability Limits of CH4/O2 Mixtures With Varying N2 Dilution at Sub-Atmospheric Conditions

This paper presents experimentally determined laminar burning speeds (SL) of premixed methane/oxygen/nitrogen mixtures at sub-atmospheric conditions obtained by using the constant-pressure spherical flame method. The goal conducted experiments was to investigate effects nitrogen dilution and pressure reduction on speed flammability limits methane/oxygen mixtures. Nitrogen content varied between 3.1 79.3 volume percent. SL a target 0.5 bar investigated. Actual levels ranged 0.506 0.568 bar. Experiments 1 were as benchmark case setup compared results from literature. is found increase with decreasing pressure. show good agreement simulated data several chemical reaction mechanisms within 4.8% for near stochiometric upper limit (UFL) shown be pressure-sensitive while lower (LFL) remains stationary both reference Furthermore, LFL stay 6% vol methane content, independent ratio.