Computational study on the effect of turbulence intensity and pulse frequency in soot concentration in an acetylene diffusion flame

Abstract

A computational investigation of the effect of turbulence structure in the formation and depletion of soot in non-premixed acetylene turbulent diffusion flames is presented. Two separate modelling approaches are investigated: 1. Realizable k-ε turbulence model combined with non-adiabatic strained laminar flamelets to solve the reaction mechanisms accounting for the effect of non-equilibrium species and, 2. Standard k-ε turbulence model and Eddy-Break-Up -EBU-with volumetric global reaction and Eddy-Dissipation model for chemistry. In both cases the results obtained show that increments in the input Reynolds number yield lower concentrations of soot. It was also found that low frequency sinusoidal pulse in the fuel inlet velocity can contribute to further reduce the soot concentration in the flame. The soot and nuclei source codes were solved as post-processed scalars and considered to be "passive" species. © Springer-Verlag Berlin Heidelberg 2005.