非稳态雷暴冲击风场的瞬态数值模拟

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振动与冲击 ›› 2017, Vol. 36 ›› Issue (3) : 51-57.

论文

非稳态雷暴冲击风场的瞬态数值模拟

汪之松1,2，王超3，刘亚南1，李正良1,2

作者信息 +

Transient numerical simulation for unsteady-state downburst winds

WANG Zhisong1,2,WANG Chao3,LIU Yanan1,LI Zhengliang1,2

Author information +

文章历史 +

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。本文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 one of the most commonly used simulation methods in studying the wind field of thunderstorms. Most of the previous physical tests and numerical simulations assume that the inlet velocity of the jet does not change with time, while the sinking velocity of downburst winds is continuously changing with time actually during its whole lifecycle, it gradually increases to the maximum value and then decreases in general. For wind-resistant design of significant engineering structures, it’s necessary to acquire the temporal profiles of downburst wind speed in its whole lifecycle. Here, a three-dimensional full-scale impinging jet was taken as a wind field model of downburst. The decay functions for the inlet jet velocity were given for the actual downburst，and numerical simulation was performed by adopting the large eddy simulation(LES) to acquire an unsteady-state wind field where the intensity decay information of downburst was presented. The simulation results showed that the unsteady wind field of downburst can be well simulated with this proposed method, and the results are correlated well to Andrews AFB recorded ones. These results laid a foundation for further studying wind load characteristics of unsteady downburst.

导出引用

汪之松1,2，王超3，刘亚南1，李正良1,2. 非稳态雷暴冲击风场的瞬态数值模拟[J]. 振动与冲击, 2017, 36(3): 51-57

WANG Zhisong1,2,WANG Chao3,LIU Yanan1,LI Zhengliang1,2. Transient numerical simulation for unsteady-state downburst winds[J]. Journal of Vibration and Shock, 2017, 36(3): 51-57

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