New York, airflow patterns inside a car passenger cab offer some suggestions for reducing the risk of Covid-19 transmissions while sharing rides with others, he said. researchers, including one of Indian origin.
The study, published in the journal Science Advances, used computer models to simulate the airflow inside a round car with a combination of open or closed windows.
The symbols showed that opening windows – the larger the windows the better – created airflow patterns that significantly reduced the collection of airborne particles that were exchanged between a driver and a single passenger.
The researchers found that the car’s ventilation system did not circulate air as well as a few open windows.
“Driving around with the windows up and the air or heat on is the worst case scenario, according to our computer simulations,” said study author Asimanshu Das from Brown University in the US.
“The best position we found was for the four windows to be open, but even one or two openings were far better than closing them all,” Das said.
The computer models used in the study were similar to a car, quickly based on a Toyota Prius, with two occupants – a driver and a passenger seated in the rear seat on the opposite side from the driver.
The researchers chose this seating arrangement because it increases the physical distance between the two (although it is still less than the 6 feet recommended by the CDC).
The models would simulate the airflow around and inside a car moving at 50 miles per hour, as well as the movement and density of aerosols coming from both driver and passenger.
Aerosols are tiny particles that can stay in the air for a long time. This is thought to be one way the SARS-CoV-2 virus is transmitted, especially in confined spaces.
The study showed that a different combination of open windows created different air currents inside the car that could either increase or decrease the remaining aerosols.
Because of the way air flows over the exterior of the car, air pressure near the rear windows tends to be higher than the pressure at the front windows.
As a result, air tends to enter the car through the rear windows and out through the front windows. With all windows open, this inclination creates two or more independent streams on either side of the cabin.
Because the occupants of the symbols were sitting on either side of the cabin, very few grains were moved between the two.
The driver in this situation is at a slightly higher risk than the passenger because the loads are average in the rear-to-front loads, but both occupants experience a lower grain movement. compared to any other situation.
The symbols found that while this arrangement is better than no windows down at all, the risk of exposure is higher compared to putting the window down in front of all occupants.
“This pattern will help reduce cross-contamination between the driver and the passenger,” the authors wrote.