This study is motivated by the amplified transmission rates of the SAR-CoV-2 virus in areas with high concentrations of fine particulates (PM) as reported in northern Italy and Mexico. To develop a deeper understanding of the contribution of PM in the propagation of the SAR-CoV-2 virus in the population the deposition patterns and efficiencies (DEs) of PM laced with the virus in healthy and asthmatic airways are studied. Physiologically correct 3-D models for generations 10-12 of the human airways were applied to carry out a numerical analysis of two-phase flow for full breathing cycles. Two concentrations of PM were applied for the simulation, i.e., 30 μg⋅m and 80 μg⋅m for three breathing statuses, i.e., rest, light exercise, and moderate activity. All the PM injected into the control volume was assumed to be 100% contaminated with the SAR-CoV-2 virus. Skewed air-flow phenomena at the bifurcations were proportional to the Reynolds number at the inlet, and their intensity in the asthmatic airway exceeded that of the healthy one. Upon exhalation, two peak air-flow vectors from daughter branches combined to form one big vector in the parent generation. Asthmatic airway models had higher deposition efficiencies (DEs) for contaminated PM as compared to the healthy ones. Higher DEs arose in the asthmatic airway model due to complex secondary flows which increased the impaction of contaminated PM on airways’ walls.
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