论文标题
SARS-COV-2在空中运输的物理建模研究
A Physics Modeling Study of SARS-CoV-2 Transport in Air
论文作者
论文摘要
SARS-COV-2空降感染受到的健康威胁已成为国际关注的公共紧急情况。在正在进行的冠状病毒大流行期间，疾病控制和预防中心建议人们保持至少2 m的社会距离，以限制暴露于冠状病毒的风险。但是，实验数据表明，被困在湍流粉末中的被感染的气溶胶和液滴可以传播到7至8 m。我们提出了一个基于核物理学的复杂气体云的建模及其病原体条件的有效载荷。我们表明，云停止范围与吹气直径及其密度的乘积成正比。我们使用粉扑模型来确定湍流云中浮力流体的平均密度。适合实验数据的$ 1.8 <ρ_p/ρ_{\ rm air} <4.0 $，其中$ρ_p$和$ρ_p$和$ρ_{\ rm air} $是泡芙和空气的平均密度。我们证明温度变化可能导致$ {\ cal o}（\ pm 8 \％）$在极端环境冷或温暖的粉扑停止范围内。我们还证明，气溶胶和液滴可以在空中悬挂数小时。因此，一旦吹气足够缓慢，并且其连贯性消失了，最终，感染的气溶胶的扩散就会取决于环境气流和湍流。
The health threat from SARS-CoV-2 airborne infection has become a public emergency of international concern. During the ongoing coronavirus pandemic, people have been advised by the Centers for Disease Control and Prevention to maintain social distancing of at least 2 m to limit the risk of exposure to the coronavirus. Experimental data, however, show that infected aerosols and droplets trapped inside a turbulent puff cloud can travel up to 7 to 8 m. We propose a nuclear physics analogy-based modeling of the complex gas cloud and its payload of pathogen-virions. We show that the cloud stopping range is proportional to the product of the puff's diameter and its density. We use our puff model to determine the average density of the buoyant fluid in the turbulent cloud. A fit to the experimental data yields $1.8 < ρ_P/ρ_{\rm air} < 4.0$, where $ρ_P$ and $ρ_{\rm air}$ are the average density of the puff and the air. We demonstrate that temperature variation could cause an ${\cal O}(\pm 8\%)$ effect in the puff stopping range for extreme ambient cold or warmth. We also demonstrate that aerosols and droplets can remain suspended for hours in the air. Therefore, once the puff slows down sufficiently, and its coherence is lost, the eventual spreading of the infected aerosols becomes dependent on the ambient air currents and turbulence.
