Bivariate Stochastic Modelling of Nanoparticles
In this paper we make use of an extended form of Smoluchowski's coagulation equation to simulate the growth and morphology of nanoparticles in premixed laminar flames. The extended model includes terms for particle inception, surface growth and particle sintering. A stochastic massflow algorithm was used to solve the model. A test simulation was implemented to examine the stochastic algorithm under various simple starting conditions. The production of SiO2 from a premixed laminar flame doped with SiH4 was investigated. A free-molecular kernel was used for the coagulation terms and a grain boundary diffusion model implemented for the particle sintering. The flame itself was simulated using a skeletal H2/O2/Ar mechanism including the SiH4 oxidation reactions. The model was able to simulate the transition from a bimodal PSD to a unimodal PSD for the silica particles produced.