Numerical studies on SiO₂ generation in swirling turbulent non‐premixed flames using SiCl₄ as the precursor

Abstract

Silica nanoparticles have been widely applied in many fields due to their excellent properties. SiO 2 generation is crucial for silica particle formation, but in a swirling reactor the SiO 2 generation is still unclear. In this study, numerical simulations are performed to investigate the SiO 2 generation and distributions of temperature and velocity during silica particle synthesis using a swirling reactor. A computational model is first developed to describe the heat and mass transport in the swirling turbulent flame. Simulation models are validated with experimental data in the case without SiO 2 chemistry. Then, effects of the fuel velocity and swirl number on SiO 2 generation are investigated. Results show that most of the SiO 2 molecules are generated in the region far away from reactor inlets and a relatively high SiO 2 generation efficiency is obtained for a fuel velocity of 32.7 m/second. Distributions of the flame temperature, velocity and SiO 2 concentration are found to vary with the swirl number and high chemical reaction rates for SiO 2 generation are obtained when a swirl number of 0.5 is employed. Uncertainty analysis shows that the average relative errors of the results from different models are within 18%. K E Y W O R D S chemical reaction, flame, reactor, silica particle, simulation