数值模拟引导的低矮建筑风压系数规范比较研究

采用基于RANS的SST（Shear Stress Transport）k-ω湍流模型对不同屋面坡角下双坡屋顶低矮建筑的表面风压及周围定常风场进行数值模拟，深入分析了坡角对结构周围流场及其表面风压的影响．在理解建筑周围流场结构的基础上，对中美澳3国风荷载规范中关于封闭式双坡屋顶低矮建筑主体结构的相关规定做了详细比较．结果表明，采用SST k-ω模型结合适当的边界条件，可较准确地预测结构表面平均风压系数及周围定常流场；分析建筑周围流场结构有助于理解并对比分析规范中的相应规定．通过规范比较可知，中国规范相对简单，关澳规范则较为详细的考虑了屋面坡角、建筑长宽比、气流分离及再附着等因素对风压系数的影响．最后，结合数值模拟的结论，给出中国规范相应规定的细化建议．

Research on Codes of Pressure Coefficient of Low-Rise Building with Numerical Simulation

A numerical study is carried out, with RANS based SST （Shear Stress Transport） k-ω turbulent model, to simulate mean wind pressure on and flow pattern around gable-roofed low-rise build- ing under different roof angles. Roof angle＇ s effects on flow pattern and building pressure are thoroughly studied. In this paper, a detailed pressure coefficient comparison research is made among Chinese code, American code and Australian code. Satisfactory numerical results of building pressure coefficients and flow pattern could be acquired by using SST k-ω model with proper boundary conditions. Researching flow pattern around building is helpful to understand the codes＇ provisions. Compared with the two other codes, the pressure coefficient of Chinese code is simple. American and Australian codes consider the effects of roof angle, building aspect ratio, air separation and reattachment, which proved to be necessary through numerical research. Finally, several refining suggestions for pressure coefficient in Chinese code are listed.