Experimental Investigation of Laminar Burning Velocity of Methyl Acetate/Air Mixtures at Elevated Temperatures

The chemical kinetics of small alkyl esters provide a foundational basis for understanding the behavior of larger alkyl esters, which are key constituents of practical biodiesel fuels used in advanced internal combustion engines. This study presents experimental investigations on the laminar burning velocity (LBV) of methyl acetate/air mixtures over an elevated temperature range of 367 - 714 K and equivalence ratios (ϕ) from 0.7 to 1.4, using the externally heated diverging channel method under atmospheric pressure. The experimental results are evaluated against existing data and detailed chemical kinetic models developed by Ahmed (2019), Lubrano Lavadera (2022), and Diévart (2013). The present measurements show good agreement with previously reported values across a wide range of operating conditions. Kinetic models by Ahmed (2019) and Lubrano Lavadera (2022) accurately capture the LBV trends, particularly at elevated temperatures, while the Diévart (2013) model consistently overpredicts LBV under fuel-rich conditions. Across all temperatures, the LBV follows a parabolic trend with a maximum at a slightly rich equivalence ratio (ϕ = 1.1), which is also predicted by the models. At ϕ = 1.0, the LBV increases by approximately 97% as the temperature rises from 450 K to 650 K, while the peak LBV increases by about 86% from 500 K to 700 K, indicating a strong temperature dependence. Sensitivity analysis highlights the dominant role of reactions involving C₀ - C₄ species in governing the combustion behavior of methyl acetate/air mixtures.