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 high temperature (high viscosity) layer formed by the burning surface and the turbulent structures generated at the dynamic shear layers. In addition, in confined flows, buoyancy effects and recirculation of large turbulent structures have to be taken into account. The study of the instantaneous phenomena of the reaction zone and of the flame tip provide valuable information about the turbulent structures and hence the mixing mechanisms in the different stages of a coaxial high temperature diffusion flame.