Turbulent flow-induced vortex formation and nonlinear spatial behavior influencing nanoparticle mixing in thermal plasma reactors

초록

In this study, we numerically investigated the fluid dynamic behavior of thermal plasma reactors using magnetohydrodynamics (MHD) to facilitate the application of Radio Frequency Inductively Coupled Plasma (RF-ICP) torch simulation for nanoparticle synthesis. A comprehensive numerical model was developed to elucidate the dynamics and growth mechanisms of micro- and nanoparticles. For microparticles, the particle method was employed to account for the build-up of electric charges, while the nodal method was adopted for nanoparticles to mitigate computational challenges associated with high nucleation densities while incorporating size distributions. Using this hybrid approach, which integrates the Lagrangian and Eulerian schemes, we obtained the size distributions of Sn nanoparticles by systematically varying the particle injection nozzle length. The simulation results revealed that at high quenching gas flow rates, particles tend to rotate along similar trajectories. The use of multiple quenching gas ports introduced additional vortices, resulting in nonlinear phenomena characterized by extended particle orbits. Furthermore, the spatial distribution of nanoparticles demonstrated greater sensitivity to gas flow due to turbulent effects and additional physical mechanisms, including boiling, evaporation, condensation, the Kelvin effect, drag force, gravity, coagulation, and nucleation. These findings highlight that the spatial distribution of nanoparticles exhibits pronounced nonlinear behavior under the combined influence of turbulence and effective forces. The results provide critical insights into the complex dynamics governing nanoparticle synthesis in RF-ICP reactors, paving the way for the optimization of process conditions and improved control over nanoparticle growth and distribution. © 2026

키워드