Research On Topological Characteristics Of Urban Air Duct Based On Complex Network Theory

In recent years,China has vigorously developed urban economy,and its population has gathered in urban areas.Urban land is becoming increasingly tense.Urban construction is developing in two directions: the increase in building height and the increase in building density.It can use land resources efficiently,to a certain extent.It eased the tense situation of land use,but it also caused many environmental problems.The large-scale development of the city has made the underlying surface rougher and the ventilation efficiency of the city has been greatly affected.At the same time,industrial production and human life's exhaust gas,smoke and automobile exhaust are not discharged in the city in time,resulting in a decline in urban air quality,which has led to many urban climate problems,such as urban heat island effect and air pollution.Wait.The urban wind environment directly affects the city's air circulation and urban climate.Therefore,in urban planning and design,rational planning of urban ventilation channels will help improve the internal ventilation of the city,enable the timely dissemination of pollutants within the city,and timely regulate the urban climate,thereby reducing the climate of air pollution and heat island effect.The problem occurred.As the internal structure of modern cities becomes more complex and diverse,simple traditional,single-angle urban ventilation models are becoming less and less applicable.The 21 st century is a century of complexity,and the system has also become a major research object,and complex networks are a tool for describing complex systems.In view of this,in order to carry out research more systematically,scientifically and comprehensively,this paper selects complex networks to conduct in-depth discussion and analysis of urban airways.The main work is as follows:Firstly,the principle of geometric relationship between buildings and their shadow imaging is elaborated.The height of the simulated regional buildings is extracted based on Google Earth images,which provides the theoretical basis and data foundation for the establishment of the next simulation three-dimensional model.Then,with the support of CFD related theory and software,combined with the actual situation of the simulation area,the wind environment numerical simulation of the simulated area is carried out,and the wind environment distribution cloud map in the area is obtained.Finally,a complex network model of urban ventilation ducts is constructed based on ArcGIS software.Based on the CFD simulation results,each air duct is quantitatively described,and the urban air duct is divided into five grades.Based on the complex network theory,using the statistical parameters of complex networks,the topological relationship and evolution law of different levels of ventilation channels are comprehensively and deeply analyzed.Finally,the characteristics of unweighted and weighted air duct networks are compared and analyzed.