Аңдатпа
The spread of respiratory viral infections in enclosed spaces remains one of the most serious threats to public health in the 21st century. The SARS and MERS epidemics, along with the COVID-19 pandemic, have demonstrated the high vulnerability of indoor building environments to the aerosol transport of pathogens. This article presents the results of numerical modeling of the transport dynamics of virus-containing particles generated during coughing within a room equipped with forced ventilation and domestic air humidification systems. The mathematical model is based on solving the three-dimensional Navier–Stokes equations for incompressible flow using the standard k–epsilon turbulence model. The Lagrangian approach is applied to describe the trajectories of the discrete phase, accounting for the effects of gravity, aerodynamic drag, Saffman lift forces, and Brownian motion. The SIMPLE numerical algorithm is implemented on a computational mesh exceeding 3.1 million elements. The adequacy of the model is confirmed by verifying the calculated velocity profiles against experimental data and the results of previous studies on cough-driven vortex ring dynamics (Renzi et al.). The study analyzes the influence of ventilation diffusers and the concentration of water vapor from domestic humidifiers on the process of droplet sedimentation and transport. It was established that during an impulsive release of particles at a velocity of 6 m/s, the maximum propagation distance reaches 2.5 m. The results show that active air humidification contributes to a decrease in aerosol concentration and a reduction of the risk zone compared to scenarios without humidity control, where the transport distance exceeds 3.5 m. It is concluded that the standard WHO recommendation for a social distance of two meters may be insufficient without accounting for the operation of indoor climate engineering systems.