Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 55 7 2023 09 23 Numerical simulation of two consecutive human sneezing and examining the dispersion of the resulting droplets in the surroundings Numerical simulation of two consecutive human sneezing and examining the dispersion of the resulting droplets in the surroundings 875 894 5274 10.22060/mej.2023.22245.7587 FA Alireza Zandaf Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran 0009-0008-5534-0316 Ghassem Heidarinejad Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran Journal Article 2023 03 05 In the present study, by simulating the process of two consecutive sneezes using a real model of the upper airway of a 65-year-old non-smoking man, the dispersion pattern of droplets resulting from the process of two consecutive sneezes has been investigated. Using computational fluid dynamics, the velocity of airflow during two consecutive sneezes was checked and the k-ω SST turbulence model was used to check the flow. Assuming realistic flow rate changes in both sneezes, the maximum flow rate during sneezing according to the subject's age and gender is equal to 553 L/min. In the present study, the simulation has been carried out by considering a wide range of droplets with diameters of 1 to 1000 microns, and about 2 million drops have been injected into the surrounding environment during the process of two consecutive sneezes. In this study, the temperature of the air in the surrounding environment and the air jet coming out of the respiratory system are assumed to be 24 and 35 degrees Celsius, and the relative humidity of the surrounding environment and the air jet is assumed to be 65 and 95%. The maximum rate of penetration and spread of droplets resulting from two consecutive sneezes in 5 seconds is 19.9 and 7.5% higher than the rate of penetration and distribution of droplets resulting from a single normal sneeze at the same time. Most of the injected droplets have evaporated in the surrounding environment during the process of two consecutive sneezes, and less than 40,000 drops are left in the environment in 5 seconds. In the present study, by simulating the process of two consecutive sneezes using a real model of the upper airway of a 65-year-old non-smoking man, the dispersion pattern of droplets resulting from the process of two consecutive sneezes has been investigated. Using computational fluid dynamics, the velocity of airflow during two consecutive sneezes was checked and the k-ω SST turbulence model was used to check the flow. Assuming realistic flow rate changes in both sneezes, the maximum flow rate during sneezing according to the subject's age and gender is equal to 553 L/min. In the present study, the simulation has been carried out by considering a wide range of droplets with diameters of 1 to 1000 microns, and about 2 million drops have been injected into the surrounding environment during the process of two consecutive sneezes. In this study, the temperature of the air in the surrounding environment and the air jet coming out of the respiratory system are assumed to be 24 and 35 degrees Celsius, and the relative humidity of the surrounding environment and the air jet is assumed to be 65 and 95%. The maximum rate of penetration and spread of droplets resulting from two consecutive sneezes in 5 seconds is 19.9 and 7.5% higher than the rate of penetration and distribution of droplets resulting from a single normal sneeze at the same time. Most of the injected droplets have evaporated in the surrounding environment during the process of two consecutive sneezes, and less than 40,000 drops are left in the environment in 5 seconds. https://mej.aut.ac.ir/article_5274_59ab3ba90ae4b4ab84fe69de7b8e3f5f.pdf