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Universal trends in human cough airflows at large distances

Updated: Mar 2, 2021

I found this interesting. It concerns coughing and the transmission of diseases via cough aerosol droplets..

As I always say, "Cure the cough and stop the spread of cough aerosol droplets." - Dennis

This, however does not have any bearing on The Weinberger Procedure and transmission of COVID-19. It would be interesting to have research into Dr. Weinberger's cure and any correlation. If you are a researcher and would like to communicate with Dr. Weinberger, please initiate communications with him via the contact page HERE.


Coughs are one of the primary means of transmission of diseases such as influenza and SARS-CoV-2 (COVID-19). Disease spreading occurs by the expulsion of pathogen containing aerosol droplets. Fine droplets can pass through layers of masks and are carried away by the exhaled airflow unlike larger droplets that settle down due to gravity. Hence, it is important to quantitatively assess the maximum distance of travel of typical human coughs with and without different types of masks. Even though near field data are available near the mouth, far field data are scarce. In this study, the schlieren method that is a highly sensitive, non-intrusive flow visualization technique is used. It can directly image weak density gradients produced by coughs. An assessment of different methods of covering the mouth while coughing is arrived at by using observations from high speed schlieren images. The effectiveness of coughing into the elbow is examined. The velocity of propagation of coughs and the distance of propagation with and without masks are quantified. It is also found that normalizing the distance–velocity profiles causes all the data to collapse onto a universal non-dimensional curve irrespective of the usage of different types of masks or test subjects. Visualization of cough flow fields and analysis of experimental data reveal that the flow physics is governed by the propagation of viscous vortex rings.

Full text from this paper is located HERE.



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