Wind tunnel tests and CFD simulations for snow redistribution on 3D stepped flat roofs
Wind tunnel tests and CFD simulations for snow redistribution on 3D stepped flat roofs
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DOI：
10.12989/was.2019.28.1.031
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发表时间：
2019
影响因子：
1.6
通讯作者：
Yu Zhixiang;Fu Zhu;Ruizhou Cao;Xiaoxiao Chen;Zhao Lei;Shichun Zhao
中科院分区：
文献类型：
--
作者：
Yu Zhixiang;Fu Zhu;Ruizhou Cao;Xiaoxiao Chen;Zhao Lei;Shichun Zhao
准确预测风作用下屋顶积雪分布对于强降雪地区土木工程结构设计具有重要作用。受建筑形状、大小、布局等因素影响，屋顶飘雪呈现出更多的立体特征。因此，需要对三维雪分布进行研究。首先设计四组宽高比分别为3、4、5、6的阶梯式平屋顶，采用平均半径为0.1mm的硅砂模拟雪粒，然后进行阶梯式平屋顶飘雪风洞试验。测试完成后使用3D扫描获得雪分布并计算平均质量传输率。接下来，根据相似性标准确定风速和持续时间以进行数值模拟。采用基于径向基函数（RBF）插值的自适应网格方法模拟较低屋顶雪相边界的动态变化，并对稳态飘雪进行时间推进分析。数值结果的总体趋势与风洞试验和现场实测基本一致，验证了数值模拟的准确性。三维典型屋顶风洞试验与CFD模拟相结合，可为典型屋顶雪荷载分布的预测提供一定的参考。
The accurate prediction of snow distributions under the wind action on roofs plays an important role in designing structures in civil engineering in regions with heavy snowfall. Affected by some factors such as building shapes, sizes and layouts, the snow drifting on roofs shows more three-dimensional characteristics. Thus, the research on three-dimensional snow distribution is needed. Firstly, four groups of stepped flat roofs are designed, of which the width-height ratio is 3, 4, 5 and 6. Silica sand with average radius of 0.1 mm is used to model the snow particles and then the wind tunnel test of snow drifting on stepped flat roofs is carried out. 3D scanning is used to obtain the snow distribution after the test is finished and the mean mass transport rate is calculated. Next, the wind velocity and duration is determined for numerical simulations based on similarity criteria. The adaptive-mesh method based on radial basis function (RBF) interpolation is used to simulate the dynamic change of snow phase boundary on lower roofs and then a time-marching analysis of steady snow drifting is conducted. The overall trend of numerical results are generally consistent with the wind tunnel tests and field measurements, which validate the accuracy of the numerical simulation. The combination between the wind tunnel test and CFD simulation for three-dimensional typical roofs can provide certain reference to the prediction of the distribution of snow loads on typical roofs.