Aerodynamics of low-rise buildings in atmospheric turbulence

在加拿大和世界各地，由于严重风暴造成的经济和保险损失继续增加。今年夏天的飓风摧毁了加勒比几个岛屿的基础设施，突出表明了这一问题的严重性。在严重的风暴中，建筑物的大部分损坏是房屋，这是最常见的结构。包层系统和屋顶部件尤其脆弱，单个屋顶板的故障可能会因雨水进入而导致重大损失。对于大规模风暴，如飓风，确定风荷载作用在建筑物的结构系统，使用边界层风洞与比例模型的方法是很好地建立。然而，用于获得用于建筑构件（诸如覆层系统）的风载荷的方法仍然没有解决。对于龙卷风，这是刚刚开始考虑在设计中的各个社区，很少有人知道的建筑物空气动力学，即使设计指导是必要的。申请人的研究计划的长期目标是减轻极端风对建筑物的影响，特别是房屋，以减少与这些风暴相关的损失，为所有加拿大人的利益，事实上，世界各地的人们。与该提案相关的短期目标涉及解决空气动力学问题，即获得建筑物构件和覆层系统上的风荷载以及龙卷风中的风荷载。在拟议的研究中要检查的问题包括以下如何影响建筑物上的风荷载：（i）风相对于屋顶表面的垂直攻角，（ii）迎面气流中的涡流，（iii）湍流强度和尺度，以及（iv）建筑物边缘的几何形状。处理飓风（和其他大规模风暴）中建筑构件和覆层系统上的风荷载以及龙卷风中的风荷载需要解决许多相同的问题。特别是，需要并将开发将在一个特定湍流风场中获得的数据修改或校正为适合于另一个湍流风场的数据的方法。例如，将飓风期间大气边界层中获得的风载荷修改为类似风速的龙卷风时的风载荷。研究方法包括利用粒子图像测速仪和表面压力测量同时进行的边界层风洞实验。六名研究生和五名本科生将通过拟议的研究在合作，国际团体环境中使用世界一流的研究基础设施进行培训，有机会发展技术研究技能，沟通技巧，沿着领导和教学机会。

Economic and insured losses due to severe storms continue to grow, both in Canada and around the world. The hurricanes this past summer, which destroyed the infrastructure on several Carribean islands, emphasize what is at stake. The majority of the damage to buildings in severe wind storms is to houses, which are the most common structures. Cladding systems and roof components are particularly vulnerable, noting that the failure of a single roof panel can lead to significant losses because of rainwater entry. For large-scale storms such are hurricanes, methods for determining the wind loads acting on the structural systems of buildings using boundary layer wind tunnels with scale models are well established. However, methods for obtaining wind loads for building components such as cladding systems are still unresolved. For tornadoes, which are just beginning to be considered in design by various communities, little is known about the building aerodynamics even though design guidance is needed.The long-term objective of the applicant's research program is to mitigate the effects of extreme winds on buildings, particularly houses, in order to reduce the losses associated with these storms, for the benefit of all Canadians and, in fact, people around the world. Short-term objectives associated with this proposal are related to resolving aerodynamic issues with respect to obtaining wind loads on building components and cladding systems as well as wind loads in tornadoes. Issues to be examined in the proposed research include how the following affect wind loads on buildings: (i) vertical angle of attack of the wind relative to the roof surface, (ii) vortices in the oncoming flow, (iii) turbulence intensity and scales, and (iv) the geometry of the building edges. Dealing with wind loads on building components and cladding systems in hurricanes (and other large-scale storms) and wind loads in tornadoes require that many of the same issues be resolved. In particular, methods to modify or correct data obtained in one particular turbulent wind field into those appropriate for another are needed and will be developed. An example of this would be applying a method to modify wind loads obtained in the atmospheric boundary layer during a hurricane into what would happen if it were a tornado of similar wind speeds.The research methods involve boundary layer wind tunnel experiments utilizing simultaneous particle image velocimetry and surface pressure measurements. Six graduate students and five undergraduate students will be trained via the proposed research using world-class research infrastructure in a collaborative, international group environment, with opportunities to develop technical research skills, communication skills, along with leadership and teaching opportunities.