Eulerian–Eulerian modeling of the formation and deposition of SiO₂ in the outside vapor deposition process

Understanding the complex phenomena in the outside vapor deposition (OVD) process is critical to improvement of the quality and production rate of optical fibers. In the current work, an Eulerian–Eulerian multiphase model based on Computational Fluid Dynamics (CFD) is proposed to simulate the physico-chemical behavior in the OVD process. The model considers the gas–solid flow, heat and mass transfer, species transport, thermodynamics of chemical reactions, as well as growth and deposition of SiO₂ comprehensively. The predicted flame structure and flow characteristics are validated against experimental measurements taken from literature. Typical transport phenomena of the OVD process are captured successfully for deeper insights into the mechanisms of the SiO₂ growth and deposition. The sensitivity of the key model constants for the solid phase is analyzed. The model predictions are insensitive to the initial particle number density of the seeds introduced. The initial particle size of the seeds critically affects the growth and deposition of SiO₂ in the OVD process. The model provides a profound understanding of the mechanism of SiO₂ growth and deposition, which plays an important role in process optimization and product attributes control.