Ahmadzadeh Mahdi, Shams Mehrzad
Faculty of Mechanical Engineering, K.N.Toosi University of Technology, Pardis St., Vanak Sq., Tehran, Iran.
J Build Eng. 2022 Aug 1;53:104544. doi: 10.1016/j.jobe.2022.104544. Epub 2022 Apr 21.
A computational fluid dynamics (CFD) simulation was performed to model and study the transmission risk associated with cough-related SARS-CoV-2 droplets in a real-world high-speed train (HST). In this study, the evaporating of the droplets was considered. Simulation data were post-processed to assess the fraction of the particles deposited on each passenger's face and body, suspended in air, and escaped from exhausts. Firstly, the effects of temperature, relative humidity, ventilation rate, injection source, exhausts' location and capacity, and adding the physical barriers on evaporation and transport of respiratory droplets are investigated in long distance HST. The results demonstrate that overall, 6-43% of the particles were suspended in the cabin after 2.7 min, depending on conditions, and 3-58% of the particles were removed from the cabin in the same duration. Use of physical barriers and high ventilation rate is therefore recommended for both personal and social protection. We found more exhaust capacity and medium relative humidity to be effective in reducing the particles' transmission potential across all studied scenarios. The results indicate that reducing ventilation rate and exhaust capacity, increased aerosols shelf time and dispersion throughout the cabin.
进行了计算流体动力学（CFD）模拟，以对现实世界高速列车（HST）中与咳嗽相关的严重急性呼吸综合征冠状病毒2（SARS-CoV-2）飞沫的传播风险进行建模和研究。在本研究中，考虑了飞沫的蒸发。对模拟数据进行后处理，以评估沉积在每位乘客面部和身体上、悬浮在空气中以及从排气口排出的颗粒比例。首先，在长途高速列车中研究了温度、相对湿度、通风率、喷射源、排气口位置和容量以及添加物理屏障对呼吸道飞沫蒸发和传输的影响。结果表明，总体而言，根据条件不同，2.7分钟后有6%-43%的颗粒悬浮在车厢内，在相同时间段内有3%-58%的颗粒从车厢中排出。因此，建议使用物理屏障和高通风率以实现个人和社会防护。我们发现更大的排气容量和中等相对湿度在所有研究场景中都能有效降低颗粒的传播潜力。结果表明，降低通风率和排气容量会增加气溶胶在整个车厢内的停留时间和扩散。
