Minji Jung ; Jin Kwan Hong
Many epidemiological studies have found that SARS-CoV-2 laden droplets from an infected human could be transmitted through the air and cause infection. CFD simulation was used to simulate the evaporation and dispersion of droplets under the Korean weather conditions. Numerical results showed that about 59% of the cough droplets evaporated to their droplet nuclei sizes (5 μm) within seconds. In quiescent air, cough droplets could travel more than 1 m and droplets less than 50 μm remained suspended for long periods, with a high concentration in the vapor plume. When the wind speed was 2.3 m/s and 2.4 m/s, which is the average wind speed of summer and winter, respectively, in Korea in 2020, droplets less than 100 μm followed the airflow streamlines and deposited on receiver 2 m away from the emitter. Therefore, based on environmental conditions, such as, wind, relative humidity, and temperature, 2 m social distancing policy may not be sufficient.