Numerical simulation of droplet aerosol transmission in an enclosed space

Abstract

A three-dimensional model of an enclosed air-conditioned space was established. Numerical simulation was conducted for the temperature distribution in the enclosed space with the air conditioner turned on using computational fluid dynamics, and the movement track of aerosol droplets exhaled by a patient in the enclosed space was traced using the discrete phase model based on the Eulerian–Lagrangian method. The analysis shows that, after the air conditioner is turned on, the velocity and temperature of outflowing air from the air conditioner greatly influence the temperature field and the movement track of aerosol in the enclosed space. With the change of intake air temperature, there is little difference in the absorption of aerosol by air conditioning; When the air velocity of outflowing air from the air conditioner is 0.8 m/s-2m/s, the amount of aerosol absorbed by the air conditioner increases with the increase of air velocity of outflowing air from the air condition. Equipping the air conditioner with an aerosol filter can prevent the aerosol droplets from exiting of the air conditioner again and decrease the quantity of aerosol particles in the enclosed space, thus reducing the risk of airborne viruses infecting susceptible people. In some public places where central air conditioning is used, aerosol filters can also avoid transmitting aerosols to other spaces through the central air conditioning system.