Experiments and Modeling of the Autoignition of Methyl-Cyclohexane at High Pressure

TL;DR

This study investigates the autoignition delays of methyl-cyclohexane mixtures at high pressure using experiments and a refined chemical kinetic model, showing improved agreement but highlighting ongoing challenges in predictive accuracy.

Contribution

The paper presents new experimental data at 50 bar and an updated chemical kinetic model for methyl-cyclohexane combustion, enhancing prediction accuracy over previous models.

Findings

Ignition delay trends are consistent across different pressures.

Updated model shows substantially improved agreement with experiments.

Work remains to improve predictions of first stage ignition delays.

Abstract

The autoignition delays of mixtures of methyl-cyclohexane (MCH), oxygen, nitrogen, and argon have been studied in a heated rapid compression machine under the conditions $P_C$ = 50 bar, $T_C$ = 690 - 910K. Three different mixture compositions were studied, with equivalence ratios ranging from $\phi$ = 0.5 - 1.5. The trends of the ignition delay measured at 50 bar were similar to the trends measured in earlier experiments at $P_C$ = 15.1 and 25.5 bar. The experimentally measured ignition delays were compared to a newly updated chemical kinetic model for the combustion of MCH. The model has been updated to include newly calculated reaction rates for much of the low-temperature chemistry. The agreement between the experiments and the model was substantially improved compared to a previous version of the model. Nevertheless, despite the encouraging improvements, work continues on further advances, e.g. in improving predictions of the first stage ignition delays.