Experimental study on laminar burning velocity and markstein length of dissociated methanol-air-diluent mixtures at elevated temperatures and pressures

Laminar burning velocities and Markstein lengths of dissociated methanol-air-diluent mixtures were measured at different equivalence ratios, initial temperatures and pressures, diluents (N₂/CO₂) and dilution ratios by using the spherically expanding flame. The influences of these parameters on laminar burning velocity and Markstein length were analyzed. The results show that laminar burning velocities of the dissociated methanol-air mixture are increased with the increase of initial temperature and are decreased with the increase of initial pressure. Peak laminar burning velocity occurs at equivalence ratio of 1.8. Markstein lengths are decreased with the increase of initial temperature and initial pressure. Mixture diluents (N₂ and CO₂) will decrease laminar burning velocities of mixtures. Markstein length increases with the increase of dilution ratio except for very lean mixture (less than 0.8). CO₂ dilution has a larger impact on laminar flame speed compared to N₂.