Soot particles inception and PAH condensation modelling applied in a soot model utilizing a sectional method

Abstract

This work aims at improving the understanding of soot formation in laminar premixed flames with a strong focus on the interactions between soot and polycyclic aromatic hydrocarbons. In this context, a soot model based on a sectional method is presented. It includes sub-models for the five main processes involved in soot formation and evolution: particle inception, condensation, coagulation, oxidation and surface growth. The two sub-models including novelties are the particle inception and the condensation ones. The nucleation sub-model proposed in the present paper is based on a dampening factor. Concerning condensation, a model taking into account its reversibility is presented and studied.This model is then validated against experimental data. Five premixed laminar flames have been selected for that purpose. They give insights into the model’s ability to predict soot formation depending on fuel, pressure and equivalence ratio. The model predictions show a good agreement with the experimental data concerning soot volume fractions as well as mean particle diameters. The influence of the modelling parameters is also studied. The reversibility of condensation appears to turn condensation into a soot consuming process which may have a significant impact on PAH profiles in premixed laminar flames.