Research On Optimal Design Of Urban Ventilation Corridors Based On CFD

As a vital part of urban microcclimate,the urban wind environment is closely linked with the diffusion of atmospheric pollutants and the dissipation of heat island effect.Urban ventilation corridors are throughout the city,and can accelerate the air circulation,ease urban heat island eflfect to a certain extent,inprove the residential living environment comfort.At present,local governments have begun to make policies on the planning and construction of urban ventilation corridors,and the research on urban ventilation corridors has gradually been paid attention to and impemented in the planning of some large cities.Based on Jinjiang city as an example,this paper used CFD(Computational Fluid Dynamics)of multi-scale numerical simulation method to explore the construction method of urban ventilation corridors and optimize the design of urban ventilation corridors through the model adjustment scheme,the main results are as follows:(1)Using meteorolbgy,geography information system as well as the computational fluid dynamics and so on multi-disciplinary knowledge and technology,drawed the wind rose and other kinds of thematic maps,determined dominant wind characteristics,specific analysis of the wind environment of Jinjiang.On the basis of ventilation corridor theory,analysis the main types of ventilated corridor,the relationship with the city the direction of the wind,and three specific components of ventilated corridor system,including corrpensation space and function space,the air guide channel.(2)Using CFD multi-scale numerical simulation method to analysis city wind conditions of macro and micro.According to "air inlet + air corridor" planning ideas,tihis paper built five primary air corridors and six of the secondary air corridors.A large number of building data from GIS to CFD are connected by generalization technology,and the 3D model is built under the research scope of macroscopic scale and microcosmic scale.After setting each parameter of model,using Linux supercomputer to calculate the model,and analyzed the wind speed at different height of the cloud,combined with the ventilation conditions such as corridor part three specific analysis,determined the overall layout of Jinjiang ventilation corridors.(3)In Jinjiang city of ventilated corridor layout,select raster calculation model and GIS platform to calculate the urban morphological parameters of the urban building Density FAD(Frontal Area Density)of the space distribution characteristics,further evaluation of the regional urban ventilation potential.Combined with CFD numerical simulation results,several different adjustment plans were formulated.To evaluate the effect of adjustment scheme,using layout sanpling point way to analysis of the variation of wind speed with height of each point under different adjustment plans and current situation.The results show that after adjusted by air inlet and ventilation buildings along the corridor,the urban wind environment has been improved to different degrees,and the urban ventilation corridors have been optimized.