Reducing chances of COVID-19 infection by a cough cloud in a closed space.
Reducing chances of COVID-19 infection by a cough cloud in a closed space.
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DOI：
10.1063/5.0029186
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发表时间：
2020-10-01
期刊：
影响因子：
--
通讯作者：
Bhardwaj R
中科院分区：
文献类型：
--
作者：
Agrawal A;Bhardwaj R
新冠肺炎感染者的咳嗽会使周围大量空气感染冠状病毒，这是因为咳嗽产生的喷流中夹带了周围的空气。在目前的工作中，我们估计了这个风量，这可能有助于我们设计封闭空间的通风，从而减少疾病的传播。最近的实验[P.P.Simha和P.S.M.Rao，“大距离人类咳嗽气流的普遍趋势”，Phys。流体32,081905(2020年)]表明咳嗽云中的速度随距离呈指数衰减。我们进一步分析数据以估计在有无面罩的情况下咳嗽云的体积。假设咳嗽云具有自相似的性质，我们发现云中夹带的体积随时间变化，其中c是传播速率，dc是咳嗽云行进的最终距离。不戴口罩时咳嗽云的体积分别是有口罩和有N95口罩时的7倍和23倍。我们还发现，对于5 S-8 S，咳嗽云是存在的，之后云开始消散，无论有无面具。我们的分析表明，咳嗽云最终达到了室温，同时保持了比周围略高的湿度。这些发现有望对了解冠状病毒的传播产生影响，据报道，冠状病毒是通过空气传播的。
The cough of a COVID-19 infected subject contaminates a large volume of surrounding air with coronavirus due to the entrainment of surrounding air in the jet-like flow created by the cough. In the present work, we estimate this volume of the air, which may help us to design ventilation of closed spaces and, consequently, reduce the spread of the disease. Recent experiments [P. P. Simha and P. S. M. Rao, “Universal trends in human cough airflows at large distances,” Phys. Fluids 32, 081905 (2020)] have shown that the velocity in a cough-cloud decays exponentially with distance. We analyze the data further to estimate the volume of the cough-cloud in the presence and absence of a face mask. Assuming a self-similar nature of the cough-cloud, we find that the volume entrained in the cloud varies as , where c is the spread rate and dc is the final distance traveled by the cough-cloud. The volume of the cough-cloud without a mask is about 7 and 23 times larger than in the presence of a surgical mask and an N95 mask, respectively. We also find that the cough-cloud is present for 5 s–8 s, after which the cloud starts dissipating, irrespective of the presence or absence of a mask. Our analysis suggests that the cough-cloud finally attains the room temperature, while remaining slightly more moist than the surrounding. These findings are expected to have implications in understanding the spread of coronavirus, which is reportedly airborne.
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影响因子：
3.7
作者：
Bourouiba, Lydia;Dehandschoewercker, Eline;Bush, John W. M.
通讯作者：
Bush, John W. M.
影响因子：
4.6
作者：
Wang, Ji-Xiang;Li, Yun-Yun;Cao, Xiang
通讯作者：
Cao, Xiang
DOI：
10.1063/5.0022859
发表时间：
2020-09-01
期刊：
Physics of fluids (Woodbury, N.Y. : 1994)
影响因子：
--
作者：
Das SK;Alam JE;Plumari S;Greco V
通讯作者：
Greco V
影响因子：
4.6
作者：
Busco, Giacomo;Yang, Se Ro;Hassan, Yassin A.
通讯作者：
Hassan, Yassin A.
影响因子：
4.5
作者：
Chao, C. Y. H.;Wan, M. P.;Katoshevski, D.
通讯作者：
Katoshevski, D.