Research On The Influence Of Ubran Road Network On The Wind Environment Of Road In Harbin In Winter

Urban road network is the structure of a city.Not only bearing the transportation function,it is the ventilation corridor of the city and the necessities of daily life.Its ventilation and internal physical environment closely affect the life of urban residents.Especially in Harbin,where winter is long and the street environment is harsh,long heating period brings serious air pollution,which brings great inconvenience to the urban residents.Therefore,it is urgent to improve the street wind environment in Harbin.This paper studys the road network and street wind environment in Harbin and analyzes the influence of these road network with different form and scale on the street wind environment.It is hoped that the optimization strategy of the wind environment in the cold region can be obtained through its influence relationshipIn this paper,firstly,the current research on wind environment with different scales at home and abroad is expounded and the fault phenomena within the existing studies are pointed out.Then through the literature review and a large number of surveys on the road network in Harbin City,it summarizes the impact factors that may change the wind environment in the road network,extracts the range of these impact factors and establishes the road network model.Finally,a numerical simulation of the road network model with different forms and scales is carried out by using the wind environment simulation software PHOENICS to obtain the effect of different factors on the wind environment of the street.The research shows that the shape and scale of urban road network have a significant impact on the wind environment of the street.Among the morphological factors,the influence of road network structure on the wind environment is the greatest,of which the grid road network has smaller wind speed and the checkered-radial road network has the larger.In different angle of the road network and unit cell morphology the wind environment also appears different when the network is the best at the angle of 30° and the cell grid aspect ratio should not equal to 1.Among the scale factors,the influence of road width on wind environment is larger than that of grid.The wind speed increases with the increase of road width and the increase of grid scale.Therefore,the city planning should be designed with small grid and narrow road,that the width of the city branch should not be greater than 20 m and the grid size should not be greater than 300 m.At last,the paper puts forward the design strategy for the road network aiming at the winter environment of urban street in Harbin with the purpose of improving road comfort.