Numerical Investigation of the Efficacy of Downward Push–Pull Air Curtain for Protecting Standing Shop-Floor Worker from Virus Transmission Through Coughing Droplets

A numerical study is carried out on downward push–pull air curtain for creating a personalized ventilated zone and preventing droplets exhaled by coughing process from entering the vicinity of a standing healthy worker in shop- floor setting. The healthy worker inside the air curtain and the cough emitter out- side is modelled using ergonomically proportioned mannequins considered to be a typical Asian male. The parameter study is conducted at constant pull velocity of 8 m/s, while the push velocity is varied such that ratios of pull to push veloci- ties are 1–8. Under the current configuration, the curtain shows concave-curtain and under-suction regime. The current configuration cannot completely shield the healthy worker from the droplets as some droplets could still penetrates the curtain, riding the entrainment between cough jet and the pull flow. Smallest number of droplets is found inside the curtain when the veolcity ratio is between 5 and 6.