LAUSR

ABSTRACT This article presents a verification and validation study of the stochastic particle-resolved aerosol model PartMC. Model verification was performed against self-preserving analytical solutions, while for validation three experiments were performed where the size distribution evolution of coagulating ammonium sulfate particles was measured in a cylindrical stainless steel chamber. To compare with the chamber measurements, PartMC was extended to include the representation of fractal particle structure and wall loss. This introduced five unknown parameters to the governing equation, which were determined by a combination of scanning electron microscopy (SEM) analysis and an objective optimization procedure. Excellent agreement between modeled and measured size distributions was achieved using the same set of parameters for all three experiments. Assuming spherical particles led to model results that were inconsistent with the measurements. The best agreement between model and measurement was obtained for the fractal dimension of 2.3, indicating that the non-spherical structure of the particle agglomerates in the chamber needed to be taken into account. © 2017 American Association for Aerosol Research