Numerical Simulation of the Aerosol Formation and Spreading in a Train Cabin

Abstract

In this paper a numerical approach for the prediction of the unsteady aerosol formation and transmission process in a train cabin is presented. For that purposes models to simulate unsteady flows including the transient behaviour of two-phase atomization process and thermal air flow are employed. Results of aerosol distribution for coughing, speaking and breathing (with and without mask) in specified train cabin compartment are discussed. The dispersion of the exhaled droplets was analysed for a double cough, 10 s talking and continuous breathing of one source passenger. The results obtained show that the dispersion of aerosol particles in the cabin after coughing is two times deeper than when speaking, 2.5 times deeper than when free breathing and 17 times deeper than when breathing with a mask. Further, the results revealed that 2 minutes after the end of the coughing, only about 6% of active aerosol particles remain in the compartment and relatively clean air is again in the cabin.

Keywords: aerosol dispersion, train compartment, computational fluid dynamics (CFD), thermal comfort model (TCM), cabin air flow, Lagrangian Multiphase Model