ABSTRACT
If a fuel and an oxidizer are supplied to a burner by two separate streams, then combustion may occur in the nonpremixed mode. In such a case, transport processes play a crucial role, because the fuel and oxidizer must be mixed in order for their molecules to collide and react. Therefore, in a nonpremixed £ame, the burning rate cannot be higher than the mixing rate and, in that sense, diffusion controls the rate of nonpremixed combustion. Accordingly, nonpremixed £ames are commonly called diffusion £ames.
