Analytical and numerical investigation of the airflow in face masks used for protection against COVID-19 virus -- implications for mask design and usage

Autor: Perić, Robinson, Perić, Milovan
Rok vydání: 2020
Předmět:
Zdroj: Journal of Applied Fluid Mechanics, Vol. 13, No. 6, pp. 1911-1923, 2020. Available online at www.jafmonline.net, ISSN 1735-3572, EISSN 1735-3645
Druh dokumentu: Working Paper
DOI: 10.47176/jafm.13.06.31812
Popis: 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.
Comment: This article is a preprint. A link to the final journal article will be posted here when the article is accepted
Databáze: arXiv