Influence of flow swirling on the aerothermodynamic behaviour of flames

The present work focuses on the numerical simulation of diffusive flames in a confined high-swirl burner. Navier–Stokes equations expressed for a time-dependent, compressible, and three-dimensional flow with finite-rate kinetics are solved for lean methane/air mixtures. A simplified mechanism is used to model the combustion. Non-reactive and reactive cases are contrasted for a swirl number of 0.95. Three flames for swirl numbers of 0, 0.6, and 0.95 are analyzed. In swirling flows, the inner recirculation zone is mainly composed of reaction products, which help in ignition of the incoming fuel. Moreover, the forward stagnation point plays an important role, leading to an azimuthal deflection of the flame front.