Insights on the nanoparticle formation process in counterflow diffusion flames

This paper reports on a new version of the multiscale atomistic model for particle inception (AMPI) code to study the effect of oxidation on nanoparticle structures formed in counter-flow, propene diffusion flames. The code has been expanded with 158 new oxidation reactions and the potential for the Molecular Dynamics module has been expanded to describe systems containing C, H and O. The rate of nanoparticle mass growth is modeled in two different flame configurations to address the influence of combustion environments on the inception process. In the case of high temperature and abundant radicals, the AMPI code successfully predicts the nanoparticle formation. In these conditions, the particle loading is mainly associated with the formation of high-molecular structures through polymerization reactions. In the case of low temperature and high polycyclic aromatic hydrocarbons (PAH) concentrations, the combined mechanism of chemical reactions described by the AMPI code and coagulation of PAH and nanoparticles contribute to particle growth. Structural properties of the particles, such as aspect ratio, oxygen content and H/C ratio are computed in the two configurations.