Experimental Investigations on Laminar Burning Velocity Variation of Methyl Formate-Air Mixtures at Elevated Temperatures

In the present work, measured laminar burning velocities of methyl formate (MF)-air mixtures at atmospheric pressure are presented for high mixture temperatures (up to 500 K) using an externally heated mesoscale diverging channel method. The experiments were performed for equivalence ratios ranging from Phi = 0.6 to Phi = 1.4 with an unburnt mixture temperature range from 350 to 500 K. The results reported in the literature and mechanism predictions of Aramco 2.0 (2016), Dievart (2013), and Dooley (2010) using PREMIX code are then compared with the data obtained from the existing experimental setup. The progressive change of temperature exponent and laminar burning velocity with equivalence ratios is akin to the other gaseous and liquid fuels outlined in the literature. The maxima and minima associated with the laminar burning velocity and temperature exponent (alpha) respectively is observed at Phi approximate to 1.1 or a slightly richer side. The mechanism predictions of the Aramco 2.0 (2016) detailed kinetic model is used for a detailed analysis of the mixture oxidation to account for the sensitivity of the key reactions on the laminar burning velocity. The overall effect of H-abstraction of methyl formate enhances the laminar burning velocity at 500 K. From reaction pathway analysis, it is observed that the global combustion rate rises when the unburnt mixture temperature changes from 348 to 500 K.