The World Health Organization has pointed out that airborne transmission via aerosol particles can be a strong vector for the spread of SARS-CoV-2. Protecting occupants from infectious diseases or harmful particulate matter (PM) in general can be challenging. While experimentally outlining the detailed flow of PM in rooms may require complex setups, computational fluid dynamics (CFD) simulations can provide insights into improving the safety of the built environment and the most effective positioning of air-purifying devices. While previous studies have typically leveraged Reynolds-averaged Navier–Stokes (RANS) approaches for predicting particle propagation, the turbulence length scales accurately captured in these simulations may not be sufficient to provide a realistic spread and the mixing of particles under the effects of forced convection. In this paper, we experimentally validate a Lattice Boltzmann very large eddy simulation (VLES) approach including particle modeling. We also demonstrate how this simulation approach can be used to improve the effectiveness of air filtration devices in realistic office environments.

Mitigating the rise and spread of contaminants is a major challenge faced during any contagious disease outbreak. In densely occupied areas, such as a breakroom, the risk of cross-contamination between healthy and infected individuals is significantly higher, thereby increasing the risk of further spread of infectious diseases. In this study, a high fidelity transient fluid solver and Lagrangian particle-based method were used to predict the airflow distribution and contaminant transmission inside a detailed 3D virtual twin of an emergency hospital breakroom. The solver efficiently captured the contaminants emitted simultaneously from multiple talking occupants as well as their propagation inside the breakroom. The influence of airflow distribution on the aerosol spread inside the breakroom for two different air conditioning vent positions was demonstrated with all occupants and with reduced occupants. The baseline simulation with all occupants in the breakroom showed a higher risk of contamination overall as well as between adjacent occupants. It was observed that there was a 26% reduction in the contaminants received by the occupants with the proposed modified vent arrangement and a 70% reduction with the scenarios considering a reduced number of occupants. Furthermore, the fomite deposition and cross-contamination between adjacent humans significantly changed with different ventilation layouts. Based on the simulation results, areas with higher contaminant concentrations were identified, providing information for the positioning of UV lights in the breakroom to efficiently eliminate/reduce the contaminants.