高大建筑物影响城市粗糙副层流场特征的数值研究  

Numerical study on effects of high-rise buildings on airflow characteristics in the urban roughness sublayer

作　　者：刘罡[1] 孙鉴泞[1,2] 王霄雪[1,3] 

机构地区：[1]南京大学大气科学学院,南京210093 [2]南京大学气候与全球变化研究院,南京210093 [3]香港大学机械工程系

出　　处：《气象科学》2012年第4期385-394,共10页Journal of the Meteorological Sciences

基　　金：国家重点基础研究发展计划(973计划)项目(2010CB428501);国家自然科学基金资助项目(40605005)

摘　　要：用数值模拟方法研究了高大建筑物对城市粗糙副层气流场特征的影响。数值模式采用基于雷诺平均纳维—斯托克斯方程组的应用计算流体力学FLUENT软件,次网格湍流参数化选用k-ε闭合方案。建筑物用立方体表示,并规则排列于模拟区域内。通过改变高大建筑物的数量与位置,对建筑物阵列内及其上空的气流特征进行了多个算例的数值模拟。依据模拟结果计算获得建筑物区域的面积平均风速廓线,结果表明各算例的粗糙副层风速廓线各不相同。运用动力学方法由风速廓线计算出各算例的零平面位移高度和粗糙度,并与几种计算零平面位移高度和粗糙度的形态学方法进行了比较检验。结果表明两种形态学方法(Ba、Ma)计算所得的零平面位移高度与动力学方法计算结果很接近,但对于粗糙度而言,几种形态学方法的计算结果都明显偏高。The effects of high-rise buildings on airflow characteristics in the urban roughness sublay- er are numerically investigated. The computational fluid mechanics software FLUENT based on the Reyn- olds-averaged Navier-Stokes equations （RANS） is employed with the k-ε closure as the sub-grid turbu- lence parameterization scheme. The buildings are represented by the cubes, which are regularly arrayed in the domain. The airflow characteristics within and above the building arrays are numerically simulated for multiple cases with the variation of number and location of the high-rise buildings. The wind speed profiles are computed and averaged in the building-occupied area. Results show that for these cases the wind speed profiles are different from one another in the urban roughness sublayer. The zero-plane dis- placement height and roughness length computed by five morphological methods are evaluated against those computed from the wind speed profiles for the cases. It is found that the zero-plane displacement heights by the two morphological methods （Ba and Ma） are close to those from the wind speed profiles, while all the morphological methods produce the roughness lengths significantly larger than those from the wind speed profiles.

关 键 词：气流 FLUENT 城市粗糙副层 粗糙度 

分 类 号：P434.4[天文地球—大气科学及气象学]