Numerical Study On Pedestrian-level Wind Environment Around Super High-rise Buildings In Equilateral Triangle Arrangement

With the continuous advancement of urbanization in China,a large number of high-rise and super high-rise buildings have emerged,and urban space is developing towards high density.Compared with single buildings,super high-rise buildings have a great impact on the air flow in the block.The wind environment around the building is more complex.The bad wind environment will reduce the comfort and safety of pedestrians ’ daily travel,and is not conducive to the diffusion of pollutants in the air.Therefore,it is necessary to study the pedestrian height wind environment of super high-rise buildings.In this thesis,numerical simulation method is used to evaluate and optimize the pedestrian wind environment under different wind direction angles and different spacing ratios.The main research work and conclusions are as follows:(1)The influence of building height,width and corner shape on pedestrian wind environment of single square section building is studied.With the increase of building height and width,the ratio of maximum wind speed to strong wind area is increasing.Under the same angle correction degree of 10 %(corner cut,chamfer and circular modification of building corner),the circular modification can provide a wider range of pedestrian comfort area,but the maximum wind speed ratio at the corner of the rounded correction building is larger than that of other sections..(2)The influence of wind direction angle and spacing ratio on pedestrian wind environment of super high-rise buildings of equilateral triangle arrangement is studied.For the maximum wind speed ratio at the corner of the building,compared with the influence of the spacing ratio of the building group,the maximum wind speed ratio is greatly affected by the wind direction angle,and the unfavorable wind direction angles are 45°,135° and 157.5°.On the contrary,the area ratio of different areas is greatly affected by the spacing ratio.With the increase of the spacing ratio,the mutual interference effect between buildings is weakened,and the pedestrian wind environment is better.Due to the unique layout of the glyph building group,different degrees of ventilation corridors will be formed between the three buildings.The wind speed amplification effect in the corridor is significant,and the bad wind environment area is concentrated in the corridor.(3)In order to improve the adverse wind environment problems of super highrise buildings of equilateral triangle arrangement,two optimization schemes of section corner correction and adding podium are proposed.In order to reduce the maximum wind speed ratio around the building,the optimization effect of the concave angle correction method is more significant.From the perspective of different area ratios,both measures can effectively reduce the area ratio of strong wind areas.The optimization effect of section corner correction from weak to strong is concave angle,tangent angle and round angle.The optimization effect of adding podium shows a trend of weakening first and then increasing with the increase of podium height.By comprehensive comparison,better optimization effect can be obtained by using the method of section corner correction.