Exposure Risk Assessment by Coupled Analysis of CFD and SIR model in Enclosed Space

The indoor environment can play a significant role in the transmission and exposure of various contaminants. In some emerging aerial infections, such as influenza virus, tuberculosis virus, and other biological and chemical contaminants, the airborne route of transmission is thought to be important to evaluate exposure health risk. In this paper, first, we present the relationship between the classic SIR model proposed by Kermack & Mckendrick and the Wells-Riley model; then, we introduce the analytical procedure of coupled analysis of computational fluid dynamics (CFD)-based prediction of unsteady contaminant concentration distribution and the basic SIR model to predict exposure risk of residents in an enclosed space.
The classic SIR model consists of three differential equations coupling changes in the population of susceptibles (S), the population of infectors (I), and the population of recovery to an immune state (R). The Wells-Riley model can predict the number of susceptibles (S) as a function of infectious contaminant concentration and exposure time by respiration. Through the analysis of infectious contaminant concentration level in a large enclosure with CFD, prediction of the changes of S, I, and R becomes possible.
The results of sensitivity analysis with changes in ventilation rate and other parameters of infections for targeting a large enclosure with simple geometry showed non-uniform distribution of S, I, and R in enclosed spaces and indicated strong dependence on unsteady and inhomogeneous contaminant distribution.