Publication

Abstract : This study presents updated comprehensive gas-phase kinetic mechanism and aerosol models to predict soot formation characteristicsin ethylene-air nonpremixed flames. A main objective is to investigate the sensitivity of the soot formation rate to various chemicalpathways for large polycyclic aromatic hydrocarbons (PAH). In this study, the detailed chemical mechanism was reduced from397 to 99 species using directed relation graph (DRG) and sensitivity analysis. The method of moments with interpolative closure(MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames of pure ethylene at low strain rate sootingconditions are considered, for which the sensitivity of soot formation characteristics with respect to hetrogeneous nucleation isinvestigated. Results show that higher PAH concentrations result in higher soot nucleation rate, and that the average size of theparticles are in good agreement with experimental results. It is found that the nucleation processes (i.e., soot inception) from higherPAH precursors, coronene in particular, is critical for accurate prediction of the overall soot formation.