Modeling reversible soot nucleation with a reduced kinetic mechanism including coronene

Abstract

Reversible dimerization of coronene is implemented into a hybrid method of moment based soot model and used with a newly generated reduced mechanism for ethylene combustion. The employed semi-automated mechanism reduction approach includes a novel error function using curve matching of species mole fraction, temperature, and heat release profiles of a counterflow diffusion flame, which was added to a path flux analysis with subsequent sensitivity analysis. The generated reduced mechanism, which maintains predictability of selected higher aromatics, while drastically reducing required computational resources, was validated for species concentration of lower hydrocarbons and aromatics for laminar premixed and counterflow diffusion ethylene flames. It was then used to model reversible dimerization of coronene and to predict soot volume fraction for several laminar premixed flames. For the analyzed cases, the combination of the newly reduced mechanism with the enhanced soot model, including reversible dimerization, was able to enhance the prediction of soot concentration trends. Finally, a discussion on uncertainties related to the equilibrium constant for dimerization is presented.