Need for wearing masks on street is shown

Specialists from India showed that when coughing on the street, a passing wind can enhance the distribution of SARS-COV-2 and spread the particles of the virus to much long distances than in calm conditions. Therefore, to prevent infection with a coronavirus infection, the masks must be worn on the street, emphasize scientists, the article of which was published in the magazine of Physics of Fluids.

Usually cough is modeled as “impulses” in the air. However, in reality, it is more difficult – it is a turbulent flow with a multitude of twist. In their work, researchers from the Indian Institute of Technology in Mumbai used a numerical hydrodynamic model imitating turbulence. Scientists simulated jets from cough in windy and normal conditions.

Simulation showed that if under normal conditions, the cough jet in 0.5 seconds, overcame 1.1 meters, even with a small concomitant stream, it overcame the same distance in 0.33 seconds. Even a small wind at a speed of about eight kilometers per hour increases the range of 20-30 percent necessary for effective social distance – from 90-182 centimeters to 109-219 centimeters. With wind speed at 14-17 kilometers per hour, the distance to which viral particles were broadcast, only increased.

Scientists have discovered that the vortex flows in the cough allow the larger drops longer than it is usually assumed to remain in the air. As the cough jet spread, it begins to interact with the passing wind, as a result of which large drops are held in the vortices of the jet instead of falling on the ground “An increase in the time of stay of larger droplets in the air increases the viral load transmitted through the cough stream, consequently, the chances of infection” – explained one of the authors of the Amit Agalval. Researchers recommend wearing a mask on the street, especially in wind conditions.

/Media reports.