Nanoparticle formation and growth in turbulent flows using the bimodal TEMOM

Abstract

A developed bimodal Taylor-series expansion method of moments (B-TEMOM) is first coupled with a large eddy simulation (LES) model to investigate nanoparticle formation and subsequent growth due to nucleation, coagulation and condensation processes in turbulent flows. An incompressible gas mixture containing sulfuric acid and water vapor is injected into a stationary flow field with background aerosols. The spatial and temporal particle size distribution (PSD), particle number and mass concentrations, and competition between the formation of primary and secondary particles in turbulent flows are studied. The instantaneous results demonstrate that the large coherent structures strongly affect the particle number and mass concentration distributions as well as particle polydispersity. This finding also verifies that the coherent structures enhance diffusion in the flows and finally increases particle transfer between the two modes of particles. Furthermore, the numerical simulation results obtained by the B-TEMOM are validated with those obtained by the sectional method with excellent agreement.