Soret and Dilution Effects on Premixed Flames

The structure of a wrinkled premixed flame is analysed theoretically. By assuming the reactive mixture diluted in an inert gas and a weak cross-diffusion coupling between the heat and mass fluxes. the effect of the change by the reaction of the physical gas properties (thermal conductivity. specific heat, number of molecules) and Soret and Dufour diffusions have been investigated in the limit of high activation energies. It turns out that Soret mass diffusion cannot be neglected in the study of the flame front dynamics. In contrast, the change of physical properties as well as Dufour heat diffusion generally appears to play a minor role.