为研究移动下击暴流作用下高层建筑的风荷载特性，采用可移动的冲击射流装置对高层建筑模型进行了测压试验，并通过计算流体力学方法进行数值模拟，分析了风暴移动过程中，风场中不同位置的高层建筑模型表面风压分布特性及风荷载作用机理。结果表明：风暴的移动会使风暴前缘风速加强，而使后缘风速减弱，从而使建筑表面的整体风压出现相应变化。当建筑位于风暴移动中心线上时，气流分离形成的漩涡主要出现在顶面迎风侧前沿及侧面迎风侧上角部区域，这些区域负压相对较大；建筑顶面在风暴经过时会产生较大正压。当建筑位于风暴移动中心线外时，高层建筑的来流风风向会随风暴的移动而不断发生变化；当建筑位于风暴前缘时，与来流风夹角较小的侧面会由于气流在钝体边缘的分离作用而出现较大的负压区域；当建筑位于风暴后缘时，建筑顶面角部区域会由于锥形涡的产生而出现较大负压。
Abstract
In order to study the wind load characteristics of high-rise buildings under moving downburst, a pressure test was carried out on a high-rise building model by using a movable impinging jet device, and the numerical simulation was carried out by using computational fluid dynamics (CFD) method. The distribution characteristics of wind pressure on the surfaces of high-rise building model at different locations in the wind field and the mechanism of wind load during the storm movement were analyzed. The results show that the wind speed of the front flank downburst will be strengthened and those of the rear flank downburst will be weakened by the storm movement, thus making the overall wind pressure on the building surface change accordingly. When the building is located on the center line of storm movement, the eddies formed by the separation of airflow mainly occur in the front of the windward side of the top surface and the upper corner of the windward side of the side surface. These areas have relatively large negative pressure, and the top surface of the building will generate relatively large positive pressure when the storm passes. When the building is located outside the center line of storm movement, the wind direction of high-rise buildings will change with the storm movement. When the building is located at the front flank downburst, the side surface with a smaller angle to the wind will appear a larger negative pressure area due to the separation of the air flow at the edge of the bluff body. When the building is located at the rear flank downburst, the corner area on the top of the building will have a larger negative pressure due to the conical vortex.
关键词
移动下击暴流 /
高层建筑 /
冲击射流 /
大涡模拟 /
风压系数
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Key words
moving downburst /
high-rise building /
impinging jet /
large eddy simulation /
wind pressure coefficients
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参考文献
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