Abstract This study aims to provide a multiphase approach that could better consider the snow drifting development on a building roof and then apply it to the investigation of the snowdrift development on a long-span spherical roof. Firstly, the CFD prediction accuracy for the flow field and the snowdrift on a two-level step building is examined by comparing simulated results with that of a field measurement. The windward snowdrift caused by building's blocking effect and trajectories of snow particles under the action of aerodynamic force and gravity are both well reproduced by incorporating an additional source term and a slip term into the transport equations. Secondly, the prediction accuracy of the snowdrift formed on a spherical roof is confirmed through the comparison with a wind tunnel test. The snow slipping effect at the edge of the roof is also well reproduced by considering the angle of repose of the snow. Based the validated approach, the snowdrift characteristics on a long-span spherical roof are investigated under different inflow velocity conditions. Three kinds of distribution patterns, i.e., the full-span balanced distribution, half-span unbalanced distribution and transitional distribution between them, are observed. Furthermore, the predicted results correspond well with the resultant design codes developed by ISO 4355. Finally, the size effect of the building roof on snowdrifts is explored by simulating the snowdrift on the spherical roofs with different spans. It is found that the spherical roof would have to bear a larger snow load with the increasing roof span, namely, the long-span spherical roof has more risks due to the adverse snow load.

中文翻译：

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大跨度球形屋面积雪发育的数值模拟

摘要 本研究旨在提供一种能够更好地考虑建筑物屋面积雪发展的多阶段方法，并将其应用于大跨度球面屋面积雪发展的研究。首先，通过将模拟结果与现场测量的结果进行比较，检验了两层阶梯建筑物上流场和雪堆的 CFD 预测精度。通过在输运方程中加入额外的源项和滑移项，可以很好地再现由建筑物的阻塞效应引起的迎风雪堆和雪粒子在空气动力和重力作用下的轨迹。其次，通过与风洞试验的对比，验证了球顶积雪的预测精度。通过考虑雪的休止角，屋顶边缘的雪滑效应也得到了很好的再现。基于验证的方法，研究了大跨度球形屋顶在不同流入速度条件下的积雪特性。观察到三种分布模式，即全跨平衡分布、半跨不平衡分布和它们之间的过渡分布。此外，预测结果与 ISO 4355 制定的最终设计规范非常吻合。最后，通过模拟不同跨度球形屋顶上的积雪，探讨了建筑物屋顶对积雪的尺寸效应。研究发现，随着屋面跨度的增加，球形屋面必须承受更大的雪荷载，即：