Numerical simulation of the effect of visitor's movement on bacteria-carrying particles distribution in hospital isolation room

Visitors’ movement and shedding bacteria-carrying particles (BCPs) from their bodies are both the most important parameters which may influence the airflow field and the induced contaminant dispersion in airborne infection isolation room (AIIR). The aim of this paper is to simulate numerically the airflow induced by a visitor walking and its effects on the contaminant transport and ventilation system effectiveness. To this end, the following will be used in this numerical simulation: the Lagrangian discrete method to trace the motion of BCPs, the dynamic mesh method to simulate the visitor movement, the Eulerian RANS model to solve the airflow. The validation results of the numerical method were in full agreement with the available experimental data in the literature. The findings of the present study indicate that the visitor’s movement has a remarkable effect on the basic airflow,and the increase of the visitor moving speed can decrease the risk of infection in the AIIR. It is also found that the concentration of BCPs in the back of visitor exceeds 10 CFU/m3 and the small distance between the patient and visitor has a negative impact on increasing the BCPs infection of patient in AIIR. At the same time, it is observed that the effect of walking speed on the ventilation effectiveness index is not remarkable. Finally, the results of the present study demonstrate that the visitor’s movement plays a decisive role to increase the infection risk around the patient therefore more in-depth investigations needs to be carried out in the future.