非稳态雷暴冲击风场的瞬态数值模拟

发布时间：2018-08-29 19:33

【摘要】：冲击射流是雷暴冲击风场研究中最常用的模拟方法。大部分物理试验和数值模拟都是假定射流速度入口风速不随时间变化,而实际雷暴冲击风的下沉气流速度都是随时间连续变化的。在雷暴冲击风的全生命周期内一般会经历逐渐增大到最大值后再逐渐减小的过程。对于重要的工程结构抗风设计而言,得到雷暴冲击风全生命周期的风速时程信息十分有必要。基于冲击射流三维足尺模型模拟雷暴冲击风风场,在入口处引入一个更符合雷暴冲击风实际演化过程的衰减函数,采用大涡模拟数值分析获得了雷暴冲击风的非稳态风场,并得到其随时间衰减的瞬态演化过程。结果表明,该模拟方法可以较好地再现雷暴冲击风场的非稳态过程,为进一步讨论非稳态雷暴冲击风场中的结构风荷载特性奠定了基础。
[Abstract]:Impinging jet is the most commonly used simulation method in the research of thunderstorm impact wind field. Most of the physical experiments and numerical simulations assume that the inlet velocity of jet velocity does not change with time, while the velocity of downdraft of actual thunderstorm impact wind varies continuously with time. During the whole life cycle of thunderstorm impact wind, it usually goes through the process of increasing to the maximum value and then decreasing gradually. It is necessary to obtain the wind time history information of the whole life cycle of thunderstorm impact wind for the important engineering structure wind resistant design. Based on the 3-D full-scale model of impinging jet to simulate the wind field of thunderstorm, a attenuation function is introduced at the entrance, which is more consistent with the actual evolution process of thunderstorm impact wind. The unsteady wind field of thunderstorm impact wind is obtained by large eddy simulation numerical analysis. The transient evolution process of the decay with time is obtained. The results show that the simulation method can well reproduce the unsteady process of thunderstorm impact wind field and lay a foundation for further discussion of the structural wind load characteristics in the unsteady thunderstorm impact wind field.
【作者单位】：重庆大学土木工程学院;重庆大学山地城镇建设与新技术教育部重点实验室;湖南省建筑设计院;
【基金】：国家自然科学基金(51208537)
【分类号】：P446;TM75

【相似文献】