Simplified diffusion model for detailed and reduced reaction mechanisms

A diffusion model is proposed, which simplifies the application of reduced reaction mechanisms considerably, whereas the results agree well with computations using a more detailed constant Lewis number diffusion model. Results are presented for one-dimensional premixed burner-stabilized flames using methane/air and hydrogen/air mixtures. The diffusion model is based on unit Lewis number assumptions for most of the species. Only for H and H2 non-unit Lewis numbers are applied. As a result, the mass fractions of the elements do not change in the °ame, which implies that these element mass fractions do not have to be taken into account as additional degrees of freedom for reduced reaction mechanisms.