Dr. Renzi and the Physics of a Single Cough

Dr. Emiliano Renzi from Loughborough University in the UK is a Senior Lecturer in Applied Mathematics who recently created a mathematical model that can analyze the motion of droplets resulting from sneezes and coughs. Dr. Renzi gained his Ph.D. in Environmental Engineering with Fluid Mechanics from the University of  Rome Tor Vergata in 2006. He then worked as an ENI-MITEI Energy Fellow at MIT for several years before working as a postdoctoral research fellow at the University College Dublin. At this university he eventually moved into the role of PI on an AXA Research Fellowship until 2015 when he took his role at Loughborough as a professor. 

His recent research- which he carried out in his bedroom do to the Covid-19 pandemic- is very applicable to recent recommendations regarding the spread of coronavirus, as he has taken to using his mathematical model to look at the distance that droplets from sneezes and coughs can travel with or without a mask. He determined that the trajectory of the droplets, the motion of which is initiated by a phenomenon known as buoyant vortex, is greatly affected by how people tilt their heads at the moment they project these droplets. This buoyant vortex is essentially the motion that occurs as a result of the hot and dense air that the droplets are combined with as they leave our mouths. He also found that larger droplets can travel horizontally over two meters and smaller droplets can be given some vertical velocity as a result of this vortex, contradicting previous studies which are informing social distancing regulations today. From these surprising results, Dr. Renzi is suggesting that people cough facing downwards in addition to using masks and maintaining adequate social distancing, as his model has shown the smallest displacement of droplets with these measures in place. 

https://phys.org/news/2020-12-mini-atomic-regularly-meters.html

https://www.lboro.ac.uk/departments/maths/staff/academic/emiliano-renzi/