The impacts of surface roughness on Indoor aerodynamics of virus-laden particles: The case of contact, deposition, and resuspension

The increasing prevalence and high morbidity of the SARS-CoV-2 virus during the COVID-19 pandemic drew widespread global attention. Surface contact is among the most common ways for the infection to spread within people, especially in buildings and the built environment. The roughness characteristics of finishing materials used in buildings vary, affecting the surface's ability to deposit and resuspend any particles that come into contact with these interfaces. Resuspension of particles indoors may increase the risk of consequent exposure through inhalation. However, little is known about surface roughness characteristics' role in airborne transmission of virus-laden particles in building indoor environments. The study examines the impact of surface roughness characteristics on the airborne transmission of the SARS-CoV-2 virus, considering indoor aerodynamic forces and their influence on particle contact with surfaces, deposition, and resuspension. The study applies Ansys Fluent CFD simulation tools to investigate the effect of volumetric flow rates and air velocity on concentration, deposition, and resuspension. The study also employs an empirical model to estimate surface roughness characteristics' impacts on particle resuspension rate. The results indicate that particle concentration and deposition rates indoors increase with increasing volumetric airflow rates. The particle resuspension rates also decreased with the increasing surface roughness of indoor surface materials. The highest resuspension rate recorded was 3.3 x 10-6, and the lowest was 1.6 x 10-6 s-1. Therefore, the outcome provides information on the implications of surface material selection and its effects on indoor air quality, health, and virus transmission. The study will offer valuable information for building engineering and design professionals in combating airborne disease transmission due to indoor surface characteristics.