Shock-Tube Experiments and Chemical Kinetic Modeling Study of CH_4 Sensitized by CH_3NHCH_3

摘要

Ignition delay times of stoichiometric CH4/CH3NHCH3/O-2/Ar mixtures are measured with a shock tube in the temperature range of 1100-2000 K Different pressures (4, 8, and 18 atm) and CH3NHCH3 blending ratios (0, 0.05, 0.1, 0.2, 0.5, and 1) are explored. CH3NHCH3 promotes CH4 ignition. Correlations for the measured ignition delay times are inferred through multiple linear regression. The measured ignition delay times are compared to the predictions of a recently developed CH3NHCH3 kinetic model with C-0-C-2 reaction subsets, and a new model for CH4/CH3NHCH3/O-2/Ar mixtures is assembled and validated against the present measurements. To elucidate the effect of CH3NHCH3 on CH4 ignition, kinetic analyses including sensitivity and rate of production are performed. Perturbation of the radical pool (H, CH3, OH, and HO2) leading to the observed effects is discussed.