Respiratory droplet transmission patterns and ventilation control strategies in the high-speed train cabin
High-speed trains,characterized by their high degree of enclosure,long operation times,and high passenger density,present a challenge as respiratory droplets carrying epidemic pathogens can easily spread through the cabin air,posing a threat to passenger health.This study developed a numerical simulation method for the coupled movement of airflow and droplets within high-speed train compartments by using a discrete phase model(DPM),and verified it with field test experiments.Moreover,for addressing the challenge of effectively controlling the spread of respiratory droplets,this study also proposed a feasible ventilation scheme based on the existing air duct system of the train.The results indicate that due to their low Stokes numbers,the trajectory and diffusion mode of droplets of small-size diameter in the air are mainly controlled by the viscous resistance of the air,and that they show desired followability with the surrounding fluid in high-speed train compartments.The relative distance between the droplet source and the air return vent is a key factor in the indoor droplet movement pattern,with the longitudinal spread of droplets first increasing and then decreasing as this distance grows.Droplets from a release source in the middle area on the right side of the compartment show the widest dispersion range,while the average longitudinal transmission distance of droplets released in the front and rear areas of the compartment decreases by 44.9%and 74.3%,respectively.Furthermore,when the airflow volume from the top and side wall vents is set at a ratio of 1∶3,it contributes to restricting the movement of droplet clusters within the passenger area.The number concentration of droplets within 2.0 m distance of the source in the passenger area is reduced by 57.4%,and the total deposition of small-size diameter droplets on passenger surfaces decreases by 34.0%.This significantly reduces the overall risk of passenger infection within compartments.These findings contribute to providing a theoretical basis for the formation of environmental safety and emergency measures in high-speed train compartments,and further ensure the safety of passenger travel and the orderly operation of high-speed railways.
high-speed train cabindroplet's transmissionnumerical simulationflow controlindoor flow field
万方数据
维普
