The Study of Pathogen Particles Spread around Buildings by Considering the Pathogen Survival Time in Air

The spread of pathogen particles emitting from the windows of infective patient room is studied by Lagrangian-Eulerian approach. In this model, the continuous phase wind flow is simulated by the three-dimensional Reynolds-averaged Navier-Stokes equations coupled with RNG k - epsiv turbulence model and the dispersed phase pathogen particles are traced by Lagrangian model. The dispersed phase is injected from the window surface of patient room. By assuming no secondary infection, the concentration of pathogen around buildings is obtained for different pathogen air survival times. Numerical results indicate that the proposed two-phase Lagrangian-Eulerian model can be effectively simulating the pathogen transport around buildings and the transportation of pathogen is mainly controlled by the pathogen survival time in air, wind velocity and building arrangement. The present model is important to control the spread of airborne disease pathogen and to establish pathogen-alarm system and evacuation plan.