On reduced mechanisms for methaneair combustion in nonpremixed flames

A four-step mechanism for the combustion of methane in air in nonpremixed flames is obtained by making steady-state and partial equilibrium approximations for minor species. The model gives good predictions of laminar flame structure, including steady-state minor species, for a wide range of flame stretch and across the whole breadth of the reaction zone, including rich mixtures. A good prediction of extinction is obtained. Further reduction to a three-step or two-step mechanism is discussed.