Oxidation of Ethylene–Air Mixtures at Elevated Pressures, Part 1: Experimental Results

Shock-tube experiments have been performed to determine ignition delay times of undiluted ethylene–air mixtures for temperatures from 1003 to 1401 K, at equivalence ratios from 0.3 to 2.0, and at pressures from 1.1 to 24.9 atm. Ethylene was the focus of this study because of its importance in the oxidation of higher-order hydrocarbons. The data exhibited some interesting behavior not typically seen in other lower-order hydrocarbons. For example, the fuel-lean mixtures showed virtually no pressure dependence, whereas at stoichiometric and fuel-rich conditions the usual trend of decreasing ignition delay time with increasing pressure was seen. The results are compared with other experimental data available in the literature and to a chemical kinetics model that has been developed over the past few years using primarily high-pressure lower-order hydrocarbon ignition delay times. The original agreement between the model and experiments at the time the data were first obtained was fair at best, stressing the i...