论文标题
咳嗽产生的呼吸液滴运动
The motion of respiratory droplets produced by coughing
论文作者
论文摘要
2019年冠状病毒疾病（Covid-19）已成为一种全球大流行感染性呼吸道疾病，死亡率高和传染性。本文研究了呼吸液滴传播，这对于理解，建模和控制流行病至关重要。在目前的工作中，我们实施了流动可视化，粒子图像速度法（PIV）和粒子阴影跟踪速度计（PSTV），以测量气流和咳嗽所涉及的气流的速度，然后构建了一个物理模型，考虑了一个物理模型，考虑了在不同天气条件下液滴运动的蒸发效应。实验结果表明，咳嗽气流的对流速度随时间呈现$ t^{ - 0.7} $的关系；因此，在我们的测量域范围内，与咳嗽的距离增加了$ t {0.3} $。将这些实验结果取代到物理模型中表明，小滴（初始直径$ d \ leq $ 100 $μ$ m）蒸发到液滴核，并且具有$ d \ geq $ 500 $μ$ m的大液滴和初始速度$ u_0 \ u_0 \ e_0 \ geq $ 5 m/s超过2 m。低温和高相对湿度的冬季条件会导致更多的液滴沉降到地面，这可能是秋季和冬季第二大流行波的驱动力。
Coronavirus disease 2019 (COVID-19) has become a global pandemic infectious respiratory disease with high mortality and infectiousness. This paper investigates respiratory droplet transmission, which is critical to understanding, modeling and controlling epidemics. In the present work, we implemented flow visualization, particle image velocimetry (PIV) and particle shadow tracking velocimetry (PSTV) to measure the velocity of the airflow and droplets involved in coughing and then constructed a physical model considering the evaporation effect to predict the motion of droplets under different weather conditions. The experimental results indicate that the convection velocity of cough airflow presents the relationship $t^{-0.7}$ with time; hence, the distance from the cougher increases by $t^{0.3}$ in the range of our measurement domain. Substituting these experimental results into the physical model reveals that the small droplets (initial diameter $D \leq$ 100 $μ$m) evaporate to droplet nuclei and that the large droplets with $D \geq$ 500 $μ$m and initial velocity $u_0 \geq$ 5 m/s travel more than 2 m. Winter conditions of low temperature and high relative humidity can cause more droplets to settle to the ground, which may be a possible driver of a second pandemic wave in the autumn and winter seasons.
