| Popis: |
Diffusion effects on the burning rate of a combustible mixture have been examined on the basis of multicomponent diffusion laws. Explicit dependencies of the burning rates on the Lewis numbers, corresponding to the various binary diffusion coefficients, are established in terms of “effective” Lewis numbers. For all practical purposes the nearstoichiometric behavior of a non-dilute mixture is found to be the same as that of a mixture whose reactants are dilute in an inert (provided that, in the absence of any inert, the product is used in calculating Lewis numbers). Motivation comes from the experimental finding that the burning rate invariably has its maximum slightly on the fuel-rich side of stoichiometry, both in the presence and absence of dissociation (cool flames). The authors have previously explained the phenomenon purely on the basis of diffusion (in contrast to the current reliance on dissociation, which excludes cool flames), but used a dilute-mixture theory. That defect is here removed. |
