Effects of wind direction on the flight trajectories of roof sheathing panels under high winds
Effects of wind direction on the flight trajectories of roof sheathing panels under high winds
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DOI：
10.12989/was.2010.13.2.145
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发表时间：
2010-03
影响因子：
1.6
通讯作者：
B. Kordi;Gabriel Traczuk;G. Kopp
中科院分区：
文献类型：
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作者：
B. Kordi;Gabriel Traczuk;G. Kopp
通过使用“破坏”模型方法，研究了极端风中风向对模型房屋屋顶覆盖板飞行的影响。初始条件，故障速度，飞行轨迹和速度之间的复杂关系进行了观察。结果表明，屋盖上方的局部流场和尾流场对壁板的飞行有重要影响。例如，当初始板位置与风向倾斜，并且在屋顶边缘附近的分离流区域中时，板不会从屋顶飞出，因为所产生的气动力很小，即使在故障时的压力系数很高。对于确实飞行的面板，来自建筑物的尾流效应是飞行轨迹和速度显著变化的来源。据观察，板的水平速度范围约为破坏时屋顶高度阵风速度的20% - 95%。假定均匀、平滑流动的数值计算似乎对确定壁板速度有用;特别是，使用平均屋顶高度，3秒阵风速度为确定所研究的构型的壁板速度提供了有用的上限。然而，使用这种方法估计轨迹存在重大挑战。
By using the `failure` model approach, the effects of wind direction on the flight of sheathing panels from the roof of a model house in extreme winds was investigated. A complex relationship between the initial conditions, failure velocities, flight trajectories and speeds was observed. It was found that the local flow field above the roof and in the wake of the house have important effects on the flight of the panels. For example, when the initial panel location is oblique to the wind direction and in the region of separated flow near the roof edge, the panels do not fly from the roof since the resultant aerodynamic forces are small, even though the pressure coefficients at failure are high. For panels that do fly, wake effects from the building are a source of significant variation of flight trajectories and speeds. It was observed that the horizontal velocities of the panels span a range of about 20% - 95% of the roof height gust speed at failure. Numerical calculations assuming uniform, smooth flow appear to be useful for determining panel speeds; in particular, using the mean roof height, 3 sec gust speed provides a useful upper bound for determining panel speeds for the configuration examined. However, there are significant challenges for estimating trajectories using this method.