Flame- and flow-conditioned vorticity transport in premixed swirl combustion

This paper presents an experimental analysis of flame-induced enstrophy transport in premixed swirl combustion at Karlovitz numbers between 20-50. Such flames posses a large-scale pressure field that -- addition to the fields associated with small-scale turbulent vortices can interact density gradients produce baroclinic torque. Simultaneous tomographic particle image velocimetry and formaldehyde planar laser induced fluorescence measurements are used obtain high-resolution velocity progress-variable fields. allows statistical evaluation various terms equation. The impact small- is assessed by conditioning torque on position fluid within instantaneous flame front, brush, axially combustor. At all conditions studied, was significant contributor transport, comparable magnitude vortex stretching viscous diffusion. Enstrophy attenuation production tended occur towards reactant product sides surface, respectively. However, value also depended equally strongly Hence, both result changes through evidence vorticity dynamics combustion, geometry-dependent flow flame-generated turbulence.