Characterization of expiration air jets and droplet size distributions immediately at the mouth opening
Chao, Christopher, Wan, Man Pun, Morawska, Lidia, Johnson, Graham R., Ristovski, Zoran, Hargreaves, Megan, Mengersen, Kerrie L., Steve, Corbett, Li, Yuguo, Xie, Xiaojian, & Katoshevski, David (2009) Characterization of expiration air jets and droplet size distributions immediately at the mouth opening. Journal of Aerosol Science, 40(2), pp. 122-133.
Size distributions of expiratory droplets expelled during coughing and speaking and the velocities of the expiration air jets of healthy volunteers were measured. Droplet size was measured using the Interferometric Mie imaging (IMI) technique while the Particle Image Velocimetry (PIV) technique was used for measuring air velocity. These techniques allowed measurements in close proximity to the mouth and avoided air sampling losses. The average expiration air velocity was 11.7 m/s for coughing and 3.9 m/s for speaking. Under the experimental setting, evaporation and condensation effects had negligible impact on the measured droplet size. The geometric mean diameter of droplets from coughing was 13.5m and it was 16.0m for speaking (counting 1 to 100). The estimated total number of droplets expelled ranged from 947 – 2085 per cough and 112 – 6720 for speaking. The estimated droplet concentrations for coughing ranged from 2.4 - 5.2cm-3 per cough and 0.004 – 0.223 cm-3 for speaking.
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|Item Type:||Journal Article|
|Keywords:||Expiratory droplets, Coughing, Speaking, Interferometric Mie imaging, Particle image velocimetry|
|Subjects:||Australian and New Zealand Standard Research Classification > PHYSICAL SCIENCES (020000) > OTHER PHYSICAL SCIENCES (029900) > Biological Physics (029901)|
|Divisions:||Past > QUT Faculties & Divisions > Faculty of Science and Technology|
Past > Schools > School of Life Sciences
Past > Schools > Mathematical Sciences
Past > Schools > School of Physical & Chemical Sciences
|Copyright Owner:||Copyright 2009 Pergamon-Elsevier Science|
|Deposited On:||19 Jun 2009 13:54|
|Last Modified:||01 Mar 2012 00:07|
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