论文标题
湍流决定了暴力呼气事件中含病毒的液滴的命运
Turbulence dictates the fate of virus-containing droplets in violent expiratory events
论文作者
论文摘要
剧烈的呼气事件，例如咳嗽和打喷嚏，是液滴的两相混合物的高度非平凡的例子，这些液滴分散在不稳定的湍流中。鉴于SARS-COV-2感染引起的全球紧急情况，了解确定呼吸液滴的分散和蒸发过程的物理机制。通过呼气气流的高分辨率直接数值模拟（DNS）和液滴动力学的全面拉格朗日模型，我们确定了湍流对呼出液滴命运的关键作用。由于初始液滴尺寸的扩展相当大，我们表明液滴蒸发时间受湍流和液滴惯性的综合作用控制。当将DNS结果与使用粗粒的描述获得的DNS结果进行比较时，这种机制显然是突出的，这些描述在大多数当前的最新研究中使用的结果，当湍流波动被过滤或完全平均时，最高$ 100 \％。
Violent expiratory events, such as coughing and sneezing, are highly nontrivial examples of a two-phase mixture of liquid droplets dispersed into an unsteady turbulent airflow. Understanding the physical mechanisms determining the dispersion and evaporation process of respiratory droplets has recently become a priority given the global emergency caused by the SARS-CoV-2 infection. By means of high-resolution direct numerical simulations (DNS) of the expiratory airflow and a comprehensive Lagrangian model for the droplet dynamics, we identify the key role of turbulence on the fate of exhaled droplets. Due to the considerable spread in the initial droplet size, we show that the droplet evaporation time is controlled by the combined effect of turbulence and droplet inertia. This mechanism is clearly highlighted when comparing the DNS results with those obtained using coarse-grained descriptions that are employed in the majority of the current state-of-the-art investigations, resulting in errors up to $100\%$ when the turbulent fluctuations are filtered or completely averaged out.
