Numerical simulation of the aerosol formation and spreading in an air-conditioned train compartment

Results of simulations of the unsteady aerosol formation and spreading in a train compartment under ventilation conditions obtained using Computational Fluid Dynamics (CFD) are presented. The latter includes various models to simulate unsteady flows including the transient two-phase atomization process and thermal convection. The aerosol distributions in a ventilated train compartment are discussed analysing the predicted dispersion of the droplets exhaled by the following respiratory events: a double cough, 10 s of speaking or continuous breathing of a passenger wearing a or no mask. The results show that the aerosol particles propagate two times deeper in the compartment for the coughing event than for speaking, 2.5 times deeper than for free breathing and 17 times deeper than for breathing with a mask. Further, it is shown that 2 min after the end of the coughing event, only about 6% of active aerosol particles remain in the compartment.