ABSTRACT
In many burners and internal combustion engines, heat is released neither in the nonpremixed mode nor in the homogeneously premixed mode. For instance, in a lean, prevaporized, premixed gas turbine combustor, fuel and air are premixed, but the mixture composition is inhomogeneous and lean, that is, the mean equivalence ratio varies in space with Φ(x,t) < 1. Such a burning regime characterized by spatial variations in the equivalence ratio, which occur only in the lean (or only in the rich) domain, is often called stratiŸed combustion (Bilger et al., 2005). In other words, a stratiŸed £ame consumes spatially inhomogeneous fuel-air mixture, with the equivalence ratio never being equal to unity. A premixed £ame that is characterized by a homogeneous mean Ÿeld Φ(x,t) = const but is subject to £uctuations in Φ(x,t) also belongs to the stratiŸed combustion regime, provided that Φ(x,t) ≠ 1.
