Effects Of Urban Spatial Morphology On Microclimate For Typical Residential Districts In Southern China City

The urban spatial morphology of urban residential districts plays a very important role in urban microclimate.Optimizing the spatial pattern of residential districts, not only can effectively improve urban local microclimate (Mainly residential ventilation and solar radiation) and mitigate the urban heat island (UHI), but also can improve the comfort of residential area environment and reduce the urban energy consumption. The local climate within an urban area can be improved as well as its climate change adaptation. At present, the studies about influences between spatial morphology of urban residential districts and urban local microclimate have not gone further. Moreover, the analysis methods have a lack of quantitative analysis and comprehensive multi-factor on local climate.In this paper, numerical simulation of influences between spatial morphology of residential districts and urban local microclimate adaptation has been conducted under the condition of solar radiation. By using Fluent, based on the meteorological background of typical hot-humid climate in summer at south China, especially in Guangzhou.The paper choosing the determ inant layout to establish the computational model,and the finite volume method was used to simulate.This study mainly research the influence law of urban local microclimate and planning community construction control parameters including residential block ratio, building density, the mean height, sky-view factor and so on. And considered how to determine the calculation domain sizeto study the urban microclimate numerical simulation.In addition, a 3D CFD computational simulation coupled residential buildings, pavement and ambient air are implemented by appling different cases. According to the comparison and analysis about results of different cases, the mechanics and laws of the effects of morphologic feature in residential districts and urban local climate adaptation are investigated in this paper.The results in this study are summarized as follows:Using cylindrical computational domain to simulated the urban microclimate problem, it shows that the results without great numerical error by compared with wind tunnel test.And designing a variety of computational domain cases to determine a appropriate size of computational domain by comparison and analysis.It provide reference to simulate city microclimate problem in future.Residential ventilation effect and solar thermal radiation has an important effect on local climate of urban residential districts. The change of residential spatial form impact the urban local climate. The group block natural wind flow,air can infuse into the community hardly,and between canopy and the upper atmosphere air exchange capacity is weak. Overall ventilation ability of residential area is worse.The accumulation of pollutants can’t discharge in group,the increasing energy consumption and even affect the thermal comfort of residents. The higher mean height and sky view factor of buildings results in higher average temperature of outdoor pavement and buildings walls in residential districts,and the outdoor air temperature increase.It is suggested that reducing the density and blocking rate of buildings and considering construct a compact city space form to provide more shaded area can improve overall ventilation and heat radiation environment, thereby modulate urban local microclimate.