Impact of walking passengers on the aerosol spreading in a passenger train

We report on the experimental investigation of the spreading of aerosol particles in a train compartment. For this purpose, a moving thermal manikin is used representing a heat-releasing, standing passenger, which can be moved through the aisle with a peak walking velocity of 1 m/s on a traverse system. The results highlight the impact of the movement by showing high peaks of increased local concentrations on different seats, which are up to nine times higher compared to the average concentration on this seat. Meanwhile the mean concentration in the compartment remains almost constant, whereas on some other seats the average concentration is locally slightly decreased. In general, the movement results in a decrease of the concentration at the highest contaminated seats near the source while increasing the concentration farther away. This effect can be explained by the additional mixing of the air in the cabin. The measurements were performed for different source locations, showing the different spreading behavior originating from aisle and window seats.