Assessment of detailed kinetics models for CO formation in ethylene combustion via time-resolved laser absorption

• C 2 H 4 oxidation was studied in a shock tube by tracking CO time histories using a laser absorption diagnostic. • Key parameters related to CO formation timing and concentration were extracted from the time-resolved CO profiles. • Experimental data were compared to detailed kinetics models from the literature. • This work highlights the adavantage of using species time histories rather than global metrics for kinetics model validation and development. • Areas for model improvement are identified and discussed. The oxidation of C 2 H 4 was studied in a shock tube by tracking CO time histories using a laser absorption diagnostic in highly diluted mixtures. Experiments were conducted over a wide temperature range at near-atmospheric pressure for three equivalence ratios (ϕ = 0.5, 1.0, and 2.0). Key parameters related to CO formation timing and concentration were extracted from the time-resolved CO profiles. The results were compared with several modern detailed kinetics models from the literature revealing that, despite the many studies available on C 2 H 4 combustion chemistry, CO time histories can be used to further improve the next generation of model predictions of C 2 H 4 oxidation. Notably, the ranking of model performance based on absolute relative error was broadly consistent with findings from recent studies involving more diverse datasets and conditions. This work highlights the advantages of using species time histories—rather than relying solely on global metrics such as ignition delay times—for kinetics model validation and development. A strong feature of the current measurements is the ability to isolate the changing chemical kinetics within specific time intervals over the whole time evolution of the CO concentration. A detailed analysis with the most-accurate model showed that specific reactions can be isolated for each extracted parameter, enabling stronger constraints on model behavior and highlighting the value of the species time history as a powerful validation tool. Areas for model improvement are identified and discussed.