Fluid dynamics simulations show that facial masks can suppress the spread of COVID-19 in indoor environments
Fluid dynamics simulations show that facial masks can suppress the spread of COVID-19 in indoor environments
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DOI：
10.1063/5.0035414
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发表时间：
2020-12-01
期刊：
影响因子：
1.6
通讯作者：
Sotiropoulos, Fotis
中科院分区：
文献类型：
--
作者：
Khosronejad, Ali;Santoni, Christian;Sotiropoulos, Fotis
2019年爆发的冠状病毒病在全球造成重大生命损失和前所未有的经济损失。地球仪广泛建议保持社交距离和戴口罩，以保护他人，防止病毒通过呼吸、咳嗽和打喷嚏传播。为了扩大这些建议的科学基础，我们进行了前所未有的分辨率和现实主义的高保真计算流体动力学模拟，以阐明人类咳嗽期间有和没有口罩的唾液颗粒传输的基本物理学。我们的模拟（a）在停滞的环境气流（室内）和温和的单向微风（室外）下进行，（B）结合人体解剖学对气流的影响，（c）考虑医用和非医用级口罩，以及（d）考虑宽范围的颗粒尺寸，范围从10 μ m到300 μ m。我们发现，在室内咳嗽时，一些唾液颗粒物可以旅行高达0.48米，0.73米，和2.62米的情况下，与医疗级，非医疗级，不戴口罩，分别。因此，在室内环境中，医用或非医用级口罩都可以成功地限制唾液颗粒向他人传播。然而，在具有单向微风的室外条件下，通过面罩的泄漏流可导致唾液颗粒被夹带到身体周围的高能剪切层中，并通过湍流在长距离处非常快速地输送，从而限制了面罩的有效性。
The coronavirus disease outbreak of 2019 has been causing significant loss of life and unprecedented economic loss throughout the world. Social distancing and face masks are widely recommended around the globe to protect others and prevent the spread of the virus through breathing, coughing, and sneezing. To expand the scientific underpinnings of such recommendations, we carry out high-fidelity computational fluid dynamics simulations of unprecedented resolution and realism to elucidate the underlying physics of saliva particulate transport during human cough with and without facial masks. Our simulations (a) are carried out under both a stagnant ambient flow (indoor) and a mild unidirectional breeze (outdoor), (b) incorporate the effect of human anatomy on the flow, (c) account for both medical and non-medical grade masks, and (d) consider a wide spectrum of particulate sizes, ranging from 10 mu m to 300 mu m. We show that during indoor coughing some saliva particulates could travel up to 0.48 m, 0.73 m, and 2.62 m for the cases with medical grade, non-medical grade, and without facial masks, respectively. Thus, in indoor environments, either medical or non-medical grade facial masks can successfully limit the spreading of saliva particulates to others. Under outdoor conditions with a unidirectional mild breeze, however, leakage flow through the mask can cause saliva particulates to be entrained into the energetic shear layers around the body and transported very fast at large distances by the turbulent flow, thus limiting the effectiveness of facial masks.