Large-eddy-simulation-based multiscale modeling of TiO_2 nanoparticle synthesis in a turbulent flame reactor using detailed nucleation chemistry

摘要

In this work, we present a multiscale computational model for flame synthesis of TiO_2 nanoparticles in a turbulent flame reactor. The model is based on large-eddy simulation (LES) methodology in conjunction with detailed gas-phase chemical kinetics to accurately model the highly complicated combustion and nucleation processes in a turbulent flame. A flamelet-based model is used to model turbulence-chemistry interactions. In particular, the transformation of TiCl_4 to the solid primary nucleating TiO_2 nanoparticles is represented using an unsteady kinetic model considering 30 species and 69 reactions in order to accurately describe the important event of nanoparticle formation. The evolution of the TiO_2 number density function is tracked using the quadrature method of moments (QMOM). For validation purposes, the detailed computational model is compared against experimental data and reasonable agreement is obtained.