计算风工程中几个关键影响因素的分析与建议

Suggestion and analysis of several key factors in computational wind engineering

通过近几年进行建筑计算风工程的实践与体会,并参考国内外的一些文献,本文给出了合理选取建筑数值风洞大小、最好采用SSTk-ω或BSL雷诺应力湍流物理模型及在建筑模型中的不同区域应按不同的网格尺度要求划分网格的建议;在CFX5软件平台中,对复杂的建筑体型,可选用非结构化网格和四面体单元,对流项的插值格式宜采用接近二阶的混合格式。还选取一立方体建筑模型,通过数值模拟、现场实测和风洞实验结果的比较对建议进行了验证。最后通过未受扰动数值风洞中入口边界条件的保持,给出了适用于我国建筑工程中A、B、C、D四类地面粗糙度类别的入口湍流边界条件,可参考采用。

Through researching in the field of Computational Wind Engineering （CWE） during the recently years and summarizing the authors＇ experience and other literatures, in this paper, the author lists several rational suggestions, such as the proper size of fluid domain, the SST k-ω or BSL Reynolds stress turbulence model, which bring more accurate result during the numerical simulation, and different grid size for different position in the fluid domain. As the complicated building＇s type, the unstructured grids are employed and the order of convective term＇s discretization is near second in CFX5 software. In order to check the suggestions, the paper compares the pressure results of flowing around a cube measured in numerical simulation and at full scale. In order to practical apply, the paper suggests four different inflow boundary conditions which are fit for A,B,C,D ter- rains in china.