High-temperature oxidation kinetics of iso-octane/n-butanol blends-air mixture

A chemical kinetic mechanism of n-butanol/iso-octane blends (Model BI) was established on the basis of a n-butanol reaction submechanism and part of a high-temperature oxidation mechanism of iso-octane. Model BI was validated against laminar flame speeds, ignition delay times and JSR data, and proved to be applicable and reliable. It also found that the laminar flame speed of blends increased linearly and monotonically with the increasing ratio of n-butanol. Then detailed kinetic pathway analysis of n-butanol/iso-octane blends were performed based on Model BI to find out the reason for the accelerating effect of added n-butanol. The most influential elementary reactions were determined for the blend, and the laminar flame speed is largely negative related to the concentration of iC₄H₈, C₃H₆ and CH₃, while C₂H₄ and C₂H₃ contribute to the promotion of laminar flame speeds. Flame structures of n-butanol blending with iso-octane were also computed and correspond to the kinetic pathway analysis.