Research Of Three-dimensional Numerical Simulation Of Outdoor Thermal Environment On Block-scale

With the rapid advance of urbanization in China,urban heat island (UHI) has become increasingly evident.As an integral unit of urban,how can we ameliorate the thermal environment in block,improving the living comfort and achieving energy-saving has become a common concern among the block developers, designers and residents and an important part of UHI research. City blocks thermal environment is the combined results of natural and human factors including urban climate,spatial layout,underlying,Involving fields of study in multidisciplinary.Along with the spatial information technology development such as RS and GIS, it facilitates us to have a better crossover study.So based on the previous study, in connection with characteristics of block-scale space form and underlying surface. This paper attempted to form an visual intelligent information system integrated by Data-Model-Module-System-function of mitigetion, which will guide block plan and design. Base on the above ideas, this paper focused on the following aspects:First of all, the background and significance of research on block-scale thermal environment was summarized.Conments on study progresses in domestic and abroad found that the current study was frequently limited to single subject research, lacked of comprehensive study,the process of simulation was so complicate.However GIS(Geographic Information System) can integrate functional modules of simulation process as components to form fully functional software system and realize comprehensive study of related disciplines and technical means,making up the defects,which was the starting and innovation point of this paper.Secondly, the outdoor thermal environment measurement was carried out in a high-level residential quarter in summer in west of Hang Zhou.The distribution characteristics of outdoor thermal environment was summarized, the main factors and its inherent mechanism during the daytime was analyzed.Also,the observations provided the boundary conditions and validation data for thermal environment simulation.Thirdly,the thermal environment simulation model and data system on block-scale were summarized,which included coupled numerical model system of surface and air temperature, methods of data orgnization for GIS.The data involve weather geography data,spatial modelling data,material physical properties,which were collected on network and applicant.Fourth, an IDL(Interactive Data Language) based platform of GIS for the numerical simulation on thermal environment was builded. In which mainly described the functional design of each module. A rapid spatial modeling methods on block-scale was developed and the spatial information management was achieved;the material was identified by hyperspectral remote sensing which provide thermal physical parameters of material for the thermal environment simulation. Using the above data,the three-dimensional simulation of thermal environment on block-scale was achieved by CFD(Computational Fluid Dynamics),simulation results was visualized and a simple energy consumption was forecast.Finally, each function module was integrated as an GIS systerm.Fifth, a high-rise district in Hangzhou was simulationed.In this process, remote sensing images, plan and design drawings, physical properties of materials and measured temperature in filed were adopted. The simulation steps included rapid modeling of block, Intelligent setting for boundary types and conditions, solution set. Then the measured data was compared to the simulation results of wind and temperature field.Sixth, according to the simulation results and measurement Analysis, the paper proposed plan and design optimization strategies for the thermal environment on block-scale, which provide scientific basis for urban plan,architectural design and landscape design etc to mitigate the heat island effect on block-scale for the purpose of improving urban micro-climate.