Yes, it is recirculated. The question is - does it happens with air speed 100-200 m/s like in wind tunnel so that any particles are evacuated directly from a pa

Yes, it is recirculated. The question is - does it happens with air speed 100-200 m/s like in wind tunnel so that any particles are evacuated directly from a passenger to the vent? Or maybe it happens extremely slowly and each cough spreads just like in a room, several meters around coughing person and persists for multiple minutes before being drawn to the vent? The answer is obvious.