2D numerical model of downward push pull ventilation for protecting workers against airborne infection

Abstract

Industrial clusters contributed significantly to the spread of Covid-19 worldwide, including in Indonesia. One of the causes is that maintaining a minimum distance of 1 to 2 meters between workers is often challenging due to the plant layout and work system design limitations. Therefore, an intervention to the workstation is needed to protect industrial workers from potential exposure to Covid-19 and other airborne infections. One technology that has a high potential to be applied to solve this problem is the air curtain/personalized ventilation. This research analyzes the effectiveness of downward push-pull air curtain in protecting workers from inhaling the infected microdroplet. The extent to which the downward push-pull ventilation can withstand the burst of microdroplets was studied by varying the air speed ratios of the air curtain. A 2D simulation was carried out with Salome, OpenFOAM, and ParaView softwares. Two scenarios were tested, i.e., the distance between the person who is coughing is 0,5 and 1 meter from the air curtain. For the distance of 0,5 meter, the results showed that the optimum velocity ratio between the pushed and pulled air was 0,17 with a droplet penetration percentage of 8,98 %. While for 1 m, the optimum velocity ratio was 0,25 with a droplet penetration percentage of 5,67 %.