Influence of the Occupant’s Height on Cough Dispersion and Infection Risk Within an Indoor Environment: A Numerical Study

The SARS-CoV-2 (COVID-19) pandemic has gradually subsided, but ongoing efforts to understand and prevent future pandemics remain crucial. Computational Fluid Dynamics (CFD) plays a key role in predicting flow dynamics and dispersion of viral particles, providing insights into transmission risks. This study, employing the Eulerian-Lagrangian multiphase CFD, explores the dispersion of cough particles from an infected person towards a susceptible occupant positioned at distances of 1 m and 2 m within an indoor environment. The investigation specifically targets occupants of varying heights, ranging from 1.1 m to 1.8 m, representing distinct demographics, including a 5-year-old child, a 9-year-old child, a typical female, and a typical male. Outcomes underscore that infection risk depends on both the height of occupants, and the distance between the infected person and the occupant. Taller occupants, such as adults, face a higher risk at 1 m, while shorter occupants, such as young children, are at a higher risk at 2 m. Notably, young children manifest a comparatively lower risk when in close proximity to the infected person. This observation can be attributed to the diminished height of the cough plume with increasing distance. As the body of occupants impedes the cough plume, the resistance force causes more pronounced droplet depositions on face and body, coupled with an augmented risk of inhaling force-induced elevated droplets. This study extends its implications beyond the scope of COVID-19, expanding our comprehension of infectious respiratory disease transmission within indoor environments.