论文标题
对面膜中的气流的分析和数值研究
Analytical and numerical investigation of the airflow in face masks used for protection against COVID-19 virus -- implications for mask design and usage
论文作者
论文摘要
在文献中已建议将面罩用于公众，作为减少全球Covid-19大流行期间病毒传播的一种手段。但是，文献发现表明，大多数面具设计都无法提供可靠的保护。本文调查了以下假设：受损的保护主要是由于面具不完善的贴合，因此包含病毒传输液滴的气流可以通过缝隙进入或从面具中泄漏。通过分析和数值计算研究面罩的流体动力学。结果表明，通过简化的分析1D流模型，有效的2D-Flow模拟和3D流量模拟可以通过简化的分析1D流模型来令人满意地预测流量。目前的结果表明，已经大于0.1mm的间隙高度可能导致掩模无法满足FFP2或FFP3标准，并且对于CA的间隙高度。 1毫米，大多数气流和液滴可能会通过间隙。讨论了这些发现的含义，并提出了对现有面具设计的改进。
The use of face masks for the general public has been suggested in literature as a means to decrease virus transmission during the global COVID-19 pandemic. However, literature findings indicate that most mask designs do not provide reliable protection. This paper investigates the hypothesis that the impaired protection is mainly due to imperfect fitting of the masks, so that airflow, which contains virus-transporting droplets, can leak through gaps into or out of the mask. The fluid dynamics of face masks are investigated via analytical and numerical computations. The results demonstrate that the flow can be satisfactorily predicted by simplified analytical 1D-flow models, by efficient 2D-flow simulations and by 3D-flow simulations. The present results show that already gap heights larger than 0.1mm can result in the mask not fulfilling FFP2 or FFP3 standards, and for gap heights of ca. 1mm most of the airflow and droplets may pass through the gap. The implications of these findings are discussed and improvements to existing mask designs are suggested.
