Computational fluid dynamics simulation of SARS-CoV-2 aerosol dispersion inside a grocery store

Abstract

Grocery stores provide essential services to communities all over the world. The COVID-19 pandemic has necessitated better understanding of the transport and dynamics of aerosolized viruses, particularly for the assessment of infection transmission risk within grocery stores and for other providers of essential services. In this study, a 3D computational fluid dynamics model was developed for a medium-sized grocery store in the United States using Ansys Fluent software. Different cases were simulated of a single infected person releasing viral aerosols with and without wearing a face mask. Results showed characteristic airflow and temperature distribution patterns inside the store that can drive the indoor dispersal of viral aerosols. Unsteady spatial distribution of mean age of air was used as a metric to indirectly quantify areas of higher risk of infection. Several factors affected the localization of suspended viral aerosols. Major recirculation patterns in certain locations of the store caused by persistent eddies were primarily attributed to increased mean age of air. The maximum mean age of air in the grocery store was found to be less than 30 min. Simulation results indicate that, without wearing a face mask, the aerosol particles released from a coughing infected person can be spread throughout nearly one-quarter of the grocery store in less than 6 min. The source-control strategy with a face mask showed significant reduction of viral aerosols being dispersed indoors.

Fate of Exhaled Droplets From Breathing and Coughing in Supermarket Checkouts and Passenger Cars

“…Simulations in supermarkets include 2 discrete particle sizes of 5 and 20 μm with contact surfaces having different particle attachment efficiencies, 15 but do not take into account the size distribution of exhaled droplets as well as the evaporation of droplets after emission. Similarly, identifying high-risk areas in a grocery store based on infected individuals along a defined route and emitting viral aerosols in the range of 0.3 to 3 μm 27 also did not incorporate size distributions of exhaled droplets as well as the evaporation of droplets after emission. Simulations in passenger car cabins estimate the risk of infection from SARS-CoV-2 Delta variant during breathing and speaking in the presence of different ventilation modes 28 used particle sizes between 2.4 and 90 μm with an assumption that the droplets evaporate as soon as they are emitted.…”

A CFD-based framework to assess airborne infection risk in buildings

“…In order to reduce the geometric complexity of the model, human features can be simplified in favour of a simplified body having roughly the same surface area of an average height person, to mimic seated and/or standing positions, as done in numerous studies [ 22 , [41] , [42] , [43] ].…”

Ventilation strategies to reduce airborne transmission of viruses in classrooms: A systematic review of scientific literature

“…(5) as reported by Ref. [ 35 ]: Where is the material derivate, is the air density, t is the time, and is the location.…”