Accurate CFD Modeling of Atmospheric Boundary Layer with an Emphasis on Wind-Induced Response of Buildings

设计规范在评估建筑物的风荷载时有几个限制，可以通过使用风洞WT测试或计算流体动力学CFD模拟来克服这些限制。风洞测试通常需要很长的筹备时间(几周/几个月)来构建模型和仪器，如果利用并行计算能力，则不是CFD的情况。对大气边界层进行正确的模拟是进行精确的CFD模拟的关键。这项建议侧重于评估和提高CFD中两种边界层生成方法(即分形面粗糙度方法和一致随机离散流生成CDRFG方法)评估高层建筑风致荷载和响应的精度。首先，这两种选定的BL生成方法将被合并到瑞尔森大学的Ansys Fluent和Open Foam软件中，该软件是RWDI常用的。然后，将进行几次模拟，以找出导致使用空域的BLS的准确模拟的参数(及其范围)。一旦确定了这些参数(及其范围)，模拟将扩展到包括有和没有周围配置的建筑，以评估风致荷载和响应，这将根据Ryerson和RWDI的WT实验进行验证。本研究项目的预期成果代表了两种基于CFD的湍流边界层精确建模方法。这些方法将使RWDI能够以更低的成本更快地进行风能工程研究，同时保持准确性。这不仅对RWDI有很大的好处，而且对加拿大也有很大的好处，因为由此产生的方法最终将导致建筑物对经常由气候变化驱动的与风有关的灾害具有更强的适应能力，这是加拿大政府的优先研究领域。

Design codes have several limitations when it comes to wind load evaluation of buildings, which can be overcome by using Wind Tunnel WT testing or Computational Fluid Dynamic CFD simulations. Wind Tunnel testing typically requires a long lead time (several weeks/months) for the model construction and instrumentation, which is not the case for CFD if the parallel computational power is utilized. It is essential for an accurate CFD simulations to properly model the atmospheric Boundary Layer (BL). This proposal focuses on assessing and enhancing the accuracy of two of BL-generating methods in CFD (namely the fractal surface roughness method and the Consistent Random Discrete Flow Generation CDRFG method) to evaluate wind-induced loads and responses of tall buildings. First the two selected BL-generating methods will be incorporated on ANSYS FLUENT and Open Foam software available at Ryerson U and commonly used by RWDI. Then, several simulations will be conducted to find the parameters (and their ranges) leading to accurate simulation of BLs using empty domains. Once those parameters (and their ranges) are identified, the simulations will be extended to include buildings with and without surrounding configurations to evaluate wind-induced loads and responses, which will be validated against WT experiments at Ryerson and RWDI. The anticipated outcomes of this research project represent two accurate modeling methods for turbulent BLs using CFD. Those methods will enable RWDI to conduct wind engineering studies faster, at a lower cost while maintaining the accuracy. This will be of a great benefit to not only to RWDI, but also to Canada as the resulting methods will ultimately lead to more resilient buildings to wind-related disasters frequently driven by the climate change, which is a priority research area for the Canadian Government.