Experimental visualization of sneezing and efficacy of face masks and shields
In the present work, we propose and demonstrate a simple experimental visualization to simulate sneezing by maintaining dynamic similarity to actual sneezing. A pulsed jet with Reynolds number Re = 30 000 is created using compressed air and a solenoid valve. Tracer particles are introduced in the fl...
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Published in | Physics of fluids (1994) Vol. 32; no. 11; p. 115129 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
AIP Publishing LLC
01.11.2020
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Online Access | Get full text |
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Summary: | In the present work, we propose and demonstrate a simple experimental visualization to
simulate sneezing by maintaining dynamic similarity to actual sneezing. A pulsed jet with
Reynolds number Re = 30 000 is created using compressed air and a solenoid valve. Tracer
particles are introduced in the flow to capture the emulated turbulent jet formed due to a
sneeze. The visualization is accomplished using a camera and laser illumination. It is
observed that a typical sneeze can travel up to 25 ft in ∼22 s in a quiescent environment.
This highlights that the present widely accepted safe distance of 6 ft is highly
underestimated, especially under the act of a sneeze. Our study demonstrates that a
three-layer homemade mask is just adequate to impede the penetration of fine-sized
particles, which may cause the spreading of the infectious pathogen responsible for
COVID-19. However, a surgical mask cannot block the sneeze, and the sneeze particle can
travel up to 2.5 ft. We strongly recommend using at least a three-layer homemade mask with
a social distancing of 6 ft to combat the transmission of COVID-19 virus. In offices, we
recommend the use of face masks and shields to prevent the spreading of droplets carrying
the infectious pathogen. Interestingly, an N-95 mask blocks the sneeze in the forward
direction; however, the leakage from the sides and top spreads the sneeze in the backward
direction up to 2 ft. We strongly recommend using the elbow or hands to prevent droplet
leakage even after wearing a mask during sneezing and coughing. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1070-6631 1089-7666 |
DOI: | 10.1063/5.0030101 |