Numerical simulations of particle turbulent dispersion and deposition with implications for the spreading of airborne diseases

Identifier:  TDX:4268

Handle: https://hdl.handle.net/20.500.11797/TDX4268

Authors:  Lavrinenko, Akim

Abstract:
This doctoral thesis thoroughly investigates particle movement in turbulent flows through numerical simulations. It focuses on two scenarios: particle-laden jet flows triggered by expiratory events and buoyancy-driven turbulent flows in enclosed spaces. The research begins by evaluating numerical methodologies for predicting particle dispersion during the initial phase of a cough. The Unsteady Reynolds Averaged Navier-Stokes model captures essential features but underestimates vertical dispersion compared to fully resolved simulations. Participation in the '2022 International Computational Fluid Dynamics Challenge on Violent Expiratory Events' reveals consistent underestimation of vertical mixing in various models, particularly in Unsteady Reynolds Averaged Navier-Stokes. The study also examines the second stage of expiratory events, where pathogen-particle dynamics depend on background air currents after turbulent energy dissipation. Additionally, it explores aerosol transport in buoyancy-driven turbulent flows within enclosed spaces, showing homogeneous particle distribution over time. The work extends to dispersion and deposition of airborne solid particles in a cubical cavity with differentially heated walls, offering valuable insights into heat transfer and particle deposition. In summary, this research contributes to our understanding of particle dispersion and deposition dynamics, vital for emergency response and mitigating airborne disease transmission, by comparing simulations with experimental data and theoretical models.