Autoignition study of methyl decanoate using a rapid compression machine

Abstract Methyl decanoate (MD), a widely used surrogate of biodiesels, was investigated for its autoignition characteristics using a heated rapid compression machine (RCM). In this study, the ignition delay times (IDTs) of MD were measured at the compressed pressures of 5–20 bar, equivalence ratios varying from 0.53 to 1.60 and compressed temperatures of 633–855 K. An obvious two-stage ignition behavior was observed at low temperatures and typical negative temperature coefficient (NTC) phenomenon of total IDT was experimentally captured. The influences of compressed pressure, fuel and oxygen content, and nitrogen concentration on ignition delay times were systematically studied. The simulation results of Herbinet’s mechanism and Grana’s mechanism under variable volume simulation were compared with the experimental data. It is found that the two mechanisms qualitatively predict the autoignition features of MD but still need further optimization. In addition, reaction pathway analysis and sensitivity analysis were conducted to offer further insight into the low-to-intermediate temperature autoignition chemistry of MD.