高铁车厢内人员走动对病毒气溶胶扩散及传播的影响

the Impact of Passenger Walking on the Spread of Virus-containing Aerosols in High-speed Train Cabin

本文建立了CR400复兴号高铁车厢的全尺寸模型,基于计算流体力学(CFD)方法模拟了特定通风方式下车厢内的气流组织及温、湿度分布,并与现场实测数据进行了对比验证。利用欧拉-拉格朗日方法和动网格技术对车厢内人员行走的动态场景进行了仿真模拟,研究了行人在通道运动过程中气流流动特性的改变,温、湿度分布变化以及车厢中部喷嚏产生气溶胶的扩散传播特性。结果表明,人员走动产生的尾流湍流会破坏初始均匀的流场结构,造成涡流产生,增加温、湿度场分布不均匀性,进而造成气溶胶蒸发特性及扩散方式的改变,不同区域内气溶胶浓度的差异也将进一步对不同位置乘客的感染风险产生影响。结果可以为评估人员走动情况下高铁车厢空气质量和感染风险性提供一定数据参考。

In this paper,a full-scale numerical model of the CR400 high-speed rail cabin was established.Based on the computational fluid dynamics(CFD)method,the airflow structure and temperature/humidity distribution under a specific ventilation mode of the cabin were simulated and the results were verified with the field-measured data.The Euler-Lagrangian method and dynamic mesh model were combined to simulate the influences of passenger walking in the cabin.It further studied the changes of airflow characteristics,temperature/humidity distribution,and the spread and transmission characteristics of aerosols produced by sneezing in the cabin.The results show that the original near-uniform airflow field were disturbed by the walking passenger,creating turbulence,and increasing the nonuniformity of temperature/humidity field,which in turn had an impact on the evaporation and transmission of virus aerosols.And the different aerosols in different sections will further impact the infection risks of passengers in different areas of the cabin.It can provide reference data for assessing the air quality and infection risk of high-speed train cabins with the influences of walking passengers.