Research On The Numerical Simulation Of Pollutant Dispersion In The Resident District

Urban resident district is the main living space and activities, the air quality is closely related to people’s lives, Therefore, residential outdoor environment directly affects the health of residents. The residential outdoor environment has become the research hotspots of environment and HVAC in recent years. At the same time, the increasing of air pollution leads to the deterioration of the residential area environment, therefore, the research on the laws of pollutants diffusion in residential area has a very important significance for improving air quality.Resident district outdoor environment air flow and air quality is affected by many factors, including the dynamic factors and thermal factors. This paper mainly studied the influence of different architectural layout and wind on the outdoor environment of air flow and pollutant distribution in the view of dynamic factors. For the thermodynamic factors, A three-dimensional numerical simulation on the flow field of residential area and pollutant concentration field is conducted with FLUENT respectively in order to investigate the thermal factor affect residential area pollutant movement and diffusion.The results show that, when the speed of the coming wind is same, the change of the wind direction will effect on air flow field greatly; Different wind direction in the same layout may cause great difference of the diffusion law about the wind environment and pollutants in a community. That is related to the shape of the windward architecture and the layout of the whole community. Due to the effect of blocking of the buildings on the wind, the local turbulence around the buildings plays an important role in control of pollutants diffusion. In the place where wind speed is low and produce turbulence around the buildings, the pollutants is not easy to spread out and concentration accumulation. The variation characteristics of pollutants concentration inside the community is increase with the distance away from the pollution sources and reduce gradually.For effected by the thermodynamic factors, the simulation results show that, different thermal conditions for wind environment and the diffusion of pollutants have influence. the existence of the thermal buoyancy lift make the local turbulence strengthen, actuating range of vortex enlarge around the buildings. It benefits to the diffusion of the pollutants in the vortex but opposite to the pollutant located at the bottom of the vortex。By the method of CFD and Tecplot software post-processing of the simulation results. This paper shows the influence of wind direction, the architectural layout and the thermodynamic factors on the wind velocity field and pollutant diffusion by a visual style. The simulation results has a certain reference value for the residential area layout design and improve air quality in the residential area.