复杂地形下全风向风速比计算方法研究

为解决复杂地形环境中,输电塔线风荷载计算的地形修正系数选取问题,本文基于计算流体动力学(Computational Fluid Dynamic, CFD)手段,提出了一种以无量纲风速比为输出的数值计算方法。该方法参考COST Action 732建议的风环境模拟指导准则,对CFD中复杂地形的计算域选取、边界条件定义方式作出改进,使其能够适用于大规模批量计算。围绕Askervein山丘及我国沿海地区的一处复杂地形,结合部分风洞试验、现场实测及参考COST Action 732准则获得的风速比数据,验证了数值模拟方法的合理性。结果表明,采用本文所述风速比计算手段,能准确考虑地形、地貌对输电塔线工作高度范围内的风加速比及风剖面造成的影响,该方法的实施为复杂地形风速比数据库的建立、输电塔线的防风加固及风致灾损事故分析奠定基础。

The Study of Wind Speed Ratio Calculation in Full Wind Direction over Complex Terrain

In order to correctly consider the topographic influence during the designing of transmission line-tower system, the numerical simulation approach based on computational fluid dynamics (CFD) has been proposed in this paper by selecting the wind speed ratio as output. Taking the COST Action 732 best practice guideline for CFD simulation as reference, the appropriate selection of terrain domain and boundary conditions have been discussed in this paper. This method is designed to realize the multiple batches calculation based on the developing of supercomputer. The international collaboration project Askervein Hill has been adopt to justify the calculation performance. Furthermore, the more rugged terrain located in the South China Sea is also introduced to distinguish the difference between the improvement calculation approach and the traditional COST Action 732 suggested results. Both the comparison of wind speed ratio and normalized wind profile show the good performance of this efficient calculation approach with the changing of wind direction. The realization of the method discussed in this paper lays the foundation for the establishment of wind speed ratio database around complex terrain and the reinforcement of structure at extreme weather condition.