A fully coupled simulation of PAH and soot growth with a population balance model

Abstract

In this paper we present a detailed soot population balance model, in which soot nanoparticles are described by aggregates of primary particles composed of individual PAH molecules. This model extends the previous PAH-PP model (Sander et al., Proc. Combust. Inst. 33 (2011) 675–683). It accounts for particle rounding due to sintering and surface reaction, and fully couples the evolution of PAHs and soot particles. For the first time, the sintering process is implemented in a soot model which is used to simulate a variety of premixed laminar flames. A new model parameter data set is obtained by a two step parameter estimation against the median and coefficient of variation of experimental particle size distributions for various flames. Mass spectra and particle size distributions (PSDs) are extracted from the detailed numerical simulations and compared with experiments. By proposing a hypothesis to describe the impact of laser ablation and a simple step function as a collision efficiency model, experimental mass spectra have been qualitatively reproduced and the results fit well with the experimental PSDs.