Numerical investigation of soot-flame-vortex interaction

Numerical simulations of a planar vortex interacting with a sooting laminar diffusion flame formed by a parallel flow of acetylene and air were performed. A detailed numerical mechanism accounting for 97 gaseous species and 59 solid BIN was considered to represent the chemistry in the gas phase and the production and oxidation of soot particles. Also three different vortex strengths were considered and vortices were formed by pulsing the air or the fuel streams allowing comparisons between the calculated soot-vortex-flame interactions with LII images. Calculations adequately retrieved experimental data when the vortex was initiated at the fuel side. Differences were noted when the vortex was formed on the air side. Simulations showed that the variability of the soot volume fraction is highly correlated to the response of soot precursors to flame curvature. Soot variability in the mixture fraction space depends on the behavior of large aggregates that being characterized by high Schmidt numbers were more sensitive to the convective motion imposed by the vortex compared to the gaseous phase.