Study On Applicability Of CFD Method In Wind Circumstance Simulation Of Urban Space In Beijing

Analysis and optimization of urban wind environment has great significance forimproving the Urban Habitat quality, building a sustainable development of urban space.At present, there are three main methods of analysis of urban wind environment fieldtest, wind tunnel experiments and computer numerical simulation. CFD computernumerical simulation method is widely used due to the advantages of easy to operate,consuming smaller human and material resources, the results intuitive; PHOENICSsoftware is one of the most widely used computer numerical simulation software, and isbecoming known by more and more urban planning workers.But the current research and applications are mostly for a single model and singleproject, without adequate analysis the impact of surrounding urban environment, thesimulation applicable conditions to be used for practical planning are not clearlyclarified. Therefore, this article taking typical city block in Beijing as model of case,taking the important evaluating index of pedestrian level wind environment as contentof research, explores the applicable conditions of CFD method in simulationapplications of this type of the urban wind environment.The paper first summarizes relevant developments in the field, describes theprinciples and applications of PHOENICS, and defines the evaluation index system ofcity pedestrian level wind environment used in this study. Thus takes a typical cityblock in Beijing, for example, to determine the wind field data on the city block modelmethod logic. On this basis, adopts the PHOENICS method to simulate and comparewind environment of typical plate building block and tower building blocks under theinfluence of different surrounding areas, and also studies the impact of different levelsof road park opening space and different angle of the dominant wind direction to windenvironment of the city block.After comparing and analysis the results of above simulation, the paper finds thatthe simulation conclusions of pedestrian level wind environment drawn upon anindependently established model of the street block as object of study are not all correct.The study finds that the densely built-up areas within the neighborhood in the city oftenhave to meet the winter’s wind requirements, the pedestrian level wind speed may be controlled in a comfortable range, Street not required to separate the wind environmentsimulation. Blocks from the pedestrian level wind environment simulation is mainlyconcentrated in a small number of wide roads and large green parks and other publicspaces, and within a block adjacent through tree planting and other methods to optimizethese cases enhance the wind comfort. The paper compares the different angle of thewind environment in the building windward side with the wind simulation results, notperpendicular to the dominant wind direction and building the windward side of thesimulation of wind environment conditions. In addition, pedestrian level windenvironment surrounding high-rise buildings is simulated and analyzed, and theapplicable conditions are defined in this paper.