Turbulence role in the fate of virus-containing droplets in violent expiratory events
Turbulence role in the fate of virus-containing droplets in violent expiratory events
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DOI：
10.1103/physrevresearch.3.013091
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发表时间：
2021-01-29
影响因子：
4.2
通讯作者：
Mazzino, A.
中科院分区：
文献类型：
--
作者：
Rosti, M. E.;Cavaiola, M.;Mazzino, A.
剧烈的呼气事件，如咳嗽和打喷嚏，是液滴分散成不稳定湍流气流的两相混合物的高度不平凡的例子。由于SARS-CoV-2感染引起的全球紧急情况，了解决定呼吸道飞沫分散和蒸发过程的物理机制最近已成为优先事项。通过高分辨率的直接数值模拟（DNSs）的呼气气流和全面的拉格朗日模型的液滴动力学，我们确定的关键作用，湍流的命运呼出液滴。由于初始液滴尺寸的相当大的传播，我们表明，液滴蒸发时间控制的湍流和液滴惯性的综合作用。当将DNS结果与大多数当前最先进的调查中采用的粗粒度描述进行比较时，这种机制清楚地突出显示，当湍流波动被过滤或完全平均时，误差高达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 (DNSs) of the expiratory airflow and a comprehensive Lagrangian model for the droplet dynamics, we identify the key role of turbulence in 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.