Large-scale turbulent structures in non-premixed, oxygen enriched flames

The objectives of the present study is to improve the fundamental knowledge of mixing and combustion at a 25 kW scale in full oxygen diffusion flames. In turbulent diffusion flames, there are strong interactions between the h igh temperature thigh viscosity) layer formed by the burning surface and th e turbulent structures generated at the dynamic shear layers. In addition, in confined flows, buoyancy effects and recirculation of large turbulent st ructures have to be taken into account. The study of the instantaneous phen omena of the reaction zone and of the flame tip provide valuable informatio n about the turbulent structures and hence the mixing mechanisms in the dif ferent stages of a coaxial high temperature diffusion flame. (C) 2001 Elsev ier Science Ltd.