Abstract: The directed relation graph (DRG) method was used to reduce a detailed reaction mechanismto a skeletal mechanism for methane with specified accuracy. Strongly coupled species groups were observed in the reduction process, hence facilitating the identification of candidate skeletal mechanisms by eliminating or retaining the strongly coupled species in groups. The skeletal mechanism with an identified threshold value of 0.01 for methane oxidation and consisting of 27 species and 182 reactions was found to mimic the performance of the detailed mechanism with a high level of reliability. In this study, we found that the starting set could not simply consist of a single species such as the fuel otherwise the threshold value would need to be smaller and the created skeletal mechanism would have been larger. It simulates the flame structure well using the created skeletal mechanism in which the starting set of species consists of the fuel and oxidizer (or N2) even with the larger threshold value.

Key words: Chemical kinetics reduction, Skeletal chemistry mechanism, Directed relation graph