Simulation Study On Outdoor Environment Of Urban Residential District

In the past ten years,the urban construction and population density increased gradually,which led to the deterioration of the outdoor microenvironment of urban residential area.The reasonable architectural form layout and green form can effectively improve the human body comfort in the outdoor microenvironment.With the application of the outdoor microenvironment simulation software ENVI-met,Tianjin summer weather parameters were selected to simulate the summer outdoor microenvironment of different forms of building layout and different green forms and an actual residential area.Simultaneously the factors impact on human thermal comfort including temperature,humidity,wind velocity,UTCI value were analyzed and compared.The main work and conclusions are as follows:The evaluation criteria of outdoor thermal comfort in recent years were summarized,and the outdoor environment was evaluated by UTCI.This paper introduced the forms of different green space in residential areas and the characteristics of ENVI-met.The outdoor microenvironment of three kinds of layouts of the two building styles including the plate building and tower building was simulated by ENVI-met.The results showed that the tower building wind environment was better than plate building,while the average temperature and the UTCI within the district of plate building were less than tower construction,so the plate building can provide a more comfortable outdoor environment.Simulation study on the influence of different green forms including lawn,shrub,tree and different tree species such as Fraxinus chinensis,Platanus orientalis,Sophora japonica on residential outdoor environment was carried out.The improvement effect of lawn and shrub on the height of 1.5m pedestrian human thermal comfort was weak.The shading effect and transpiration of tall trees made a better pedestrian human thermal comfort improvement.Compared to Platanus orientalis and Sophora japonica,Fraxinus chinensis had the larger tree height,crown width and leaf area index in Tianjin and the improvement effect on micro environment of residential area was better.The outdoor microenvironment of a residential district in Tianjin was simulated and analyzed,the area of low wind velocity is large and the wind environment is poor.By changing the building orientation of the district,the average wind velocity was increased by 0.16m/s,while the average UTCI value was reduced by 0.02?,and the wind and thermal environment were improved.Based on the above,increasing Fraxinus chinensis made the UTCI value decrease 2.4?,the outdoor pedestrian thermal comfort could be significantly improved with the optimized vegetation.