Reducing the risk of droplet inhalation for taxi drivers by regulating the air supply position according to the exhalation source

The environment inside taxis is relatively closed, making it easy for the drivers to contact with droplets exhaled by the passengers and creating a high risk of respiratory diseases. To study the diffusion of droplets in taxis, the numerical simulation was performed based on gas–solid two–phase flow. The renormalization-group k–epsilon (RNG k–ε) turbulence model and the discrete phase model were used to study the transmission characteristics of droplets with different exhalation sources, and the air-supply positions were chosen to reduce the risk of driver infection from droplet inhalation. Based on the likelihood–exposure–consequence (LEC) method, the cumulative inhalation ratio of droplets was used to assess drivers’ infection risk during working. The results show that, the driver’s infection risk is least when the passenger sits in the front seat, reducing the risk by 32%–87%. Furthermore, the risk is reduced by 38%–85% when the air supply is changed from two-sided to central. Therefore, the combination that minimizes the risk of inhalation infection for taxi drivers is the passenger sitting in the front seat and the air being supplied centrally in the taxi, which can provide a reference for improving the car layout and ventilation system of the taxi.