محمدحسين ظاهر

Recent research has demonstrated that COVID-19 as an airborne disease has pro‎mp‎ted social distancing and wide-ranging application of face shields. Airborne virus transmission can happen by droplets created during respiratory tasks, such as speaking, coughing, breathing, and sneezing. This study aims to simulate the application of a face shield to hindrance carrying droplets caused by sneezing from reaching the face of a healthy person. A three-dimensional discrete phase model using the k-εe turbulent model was employed to eva‎luate different cases, including inhalation, exhalation, air conditioning system, suction ventilation, and shield geometry. The results showed that the best performance of the studied cases was considered the case with the minimum collision percentage of droplets that hit the nose and mouth of the healthy person. Considering this, the optimum speed was 2 m/s for the application of the air conditioning system. The new proposed geometry with curvature at the edges had better performance for impeding infection than the simple geometry, reducing the collision percentage by about 5%. Also, more droplets will exit the room, and fewer droplets will hit the face when the sneezing angle is changed by 45° to the right and up. Furthermore, using a hybrid case, including opening the window in front of the infectious person, applying an air conditioning system with a cross-flow to the microdroplets and a speed of 2 m/s, and utilizing the new geometry, will be the best choice (83% reduction in collision percentage compared to the optimal individual case) in a hospital room with the presence of an infectious and a healthy person.

كرونا؛ كوويد-19؛ محافظ صورت؛ تهويه مطبوع؛ سرعت بهينه

COVID-19, Face shield, microdroplets, CFD simulation, Air conditioning system

mohammad hossein zaher

salman movahedi rad