My Best of Web submission comes from a paper published from Florida Atlantic University. Researchers set out to visualize the fluid flow paths created by different mask options used to try and reduce the spread of the COVID-19 virus. They investigated the use of face shields as well as masks that used an exhalation valve. Videos were captured showing a model of a person wearing a mask simulating a cough or a sneeze. Particles from this expulsion scatter light from laser sheets, allowing the flow to be visualized. The high contrast of the bright green flow on a black background makes for stunning and relevant images.
Video courtesy of Siddhartha Verma, Manhar Dhanak, and John Frankenfield
Physics of Fluids 32, 091701 (2020); https://doi.org/10.1063/5.0022968