基于修正SSTk-ω湍流模型的建筑群风环境数值分析

Numerical simulation of wind environment around buildings based on modified SSTk-ωturbulence model

当前我国对城市小区风环境的研究还相对滞后,城市冠层内风场的详细分布还尚不明确.为揭示城市冠层流场分布,文中通过自编程序对商业软件进行了二次开发,通过添加源项的方法对传统SSTk-ω湍流模型进行了修正,基于修正SSTk-ω湍流模型对不同建筑密度、高度与错落度三种城市形态下的冠层风场进行了深入分析,获取了不同建筑形态下建筑物近地面平均风与湍动能的详细分布.研究结论显示:采用添加源项的办法可以较好的实现SSTk-ω湍流模型湍动能和速度的自保持.城市冠层风场随空间高度可分为紊乱区(h<href)、增长区(href<h<1.3href)和稳定区(h>1.3href);在紊乱区风速杂乱无章,平均风速小于规范给定的风剖面值,错落度和建筑高度可分别提升紊乱区和增长区的上限风速值.湍动能在建筑内部沿来流方向呈递减趋势,最大值一般出现在前排建筑物屋顶位置.

The current research on the urban wind environment in China is relatively lagging,and the detailed distribution of the wind field in the urban canopy is still unclear.Therefore,to obtain the distribution of the urban canopy flow field,this paper based on the modified turbulence model analyzes the urban canopy wind field in different urban building morphology.In the process,the detailed average wind velocity(AWV)and turbulent kinetic energy(TKE)near the ground are obtained.The results show that the urban canopy wind field can be divided into turbulent area(h<href),growth area(href<h<1.3href)and stable area(h>1.3href)along with heights.In the turbulent area,the wind velocity is disorderly,and the AWV is lower than the wind profile values given by the code.Building height and height differences can improve the upper limit wind speed value of the turbulent area and the growth area.TKE inside the urban canopy shows a decreasing trend along the incoming direction,and the maximum value generally appears on the roof of the front row building.