Kinetic modeling of ethylene oxidation in high speed reacting flows

A reduced chemical kinetic reaction mechanism for the combustion of ethylene fuel has been developed and validated under atmospheric pressure conditions. The reduced reaction model was derived from the full reaction mechanism of Dagaut et al. [5] which consists of 505 reactions and 78 chemical species. The approach used to develop the reduced reaction model was to start from the full ethylene mechanism and then systematically remove those reactions that are found to be unimportant following rigorous reduction criteria and testing by a sensitivity analysis. The reduced reaction model contains 9 chemical species and 8 chemical reactions. The reduced reaction mechanism was used to study the chemical kinetic behavior of ethylene-air mixture combustion. Ignition of ethylene-air mixture in a closed adiabatic constant pressure system, oxidation of ethylene in perfectly-stirred reactors and structure and burning velocity of laminar premixed ethylene-air were all investigated as a part of the reaction mechanism validation studies and the results were compared with results obtained using full detailed reaction mechanisms and existing experimental data. The numerical results show that the reduced ethylene reaction model can reproduce the kinetic results obtained from the detailed reaction models and the experimental data of premixed laminar flame speed under the same temperature, pressure and equivalence ratio conditions. It is therefore anticipated that the mechanism can be used in various combustion applications and will provide a good description of the combustion process with a substantial saving in the computational time for CFD analysis as compared to the use of detailed reaction models.