Simulation Of Unsteady Pollutant Dispersion Around Buildings Group

With the densification of population in central urban area and the deterioration of city ecological cycle, especially in developing countries, the airborne disease virus is becoming a new challenge for human. A numerical model to simulate the transport of airborne disease around buildings is established in this thesis. The numerical model can be applied to forecast the spread of airborne disease virus around buildings. It is also favorable to establish virus-alarm systems and make suitable evacuation plans.A two-dimensional numerical model with RNG k -εturbulence model is developed to simulate the diffuse and pollution concentration of the virus in a group of five buildings. The population dynamic model of virus growth is introduced as an unsteadily pollutant source. By considering secondary infection, the distribution of time-dependent concentration of disease microbial pollutant around the group of buildings and that on the sidewalls of buildings is obtained. With known pathogenic concentration, the infectious area can be determined. For the model application, the development of the flu virus around building is studied.The above two-dimensional model is further developed to a three-dimensional numerical model. The concentration of the virus in a group of buildings is obtained. It is found that the virus concentration of the two-dimensional results is similar to that of horizontal plane of three-dimensional one. The conclusion suggests that it is possible to simulate by using the two-dimensional model at first to fulfill the purpose of study and to check the applicability of two-dimensional results by making three-dimensional simulation.