雷暴冲击风具有和大气边界层显著不同的风场特性.为与抗风设计习惯一致,提出了与大气边界层风场类似的冲击风水平风荷载下静力风荷载表达式,并给出了相应的风压高度变化系数和体型系数的计算方法.以球壳型大跨屋面为具体研究对象,采用CFD数值模拟方法,研究其在冲击风作用下随结构参数和冲击风参数改变的冲击风体型系数变化规律,并将结果与大气边界层风洞实验中的结果进行比较.最后还给出了球壳屋面位于冲击风正下方时,屋面体型系数及风压高度变化系数的取值.%The wind characteristics of thunderstorm downburst are significantly different from atmospheric boundary layer. In order to be consistent with the habit of wind-resistant design, the expression of horizontal static wind load similar to boundary layer winds were proposed, and the corresponding calculation both wind pressure height coefficient and shape coefficient were concluded. Furthermore the shape coefficients of spherical roof subjected to thunderstorm downburst had been investigated via CFD simulation, by varying the parameters of structure and downburst, besides, the CFD results were compared with the results of boundary layer wind tunnel. Finally, the values of wind pressure height coefficient and shape coefficient were presented when spherical roof was located beneath the downburst.
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