风暴移动对下击暴流风场特性的影响研究  

Study on effect of storm movement on wind field characteristics of downburst

作　　者：方智远 李正良[1,2] 汪之松[1,2] FANG Zhiyuan;LI Zhengliang;WANG Zhisong(School of Civil Engineering, Chongqing University, Chongqing 400045 , China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education,Chongqing University, Chongqing 400045 , China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《建筑结构学报》2019年第6期166-174,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51208537)

摘　　要：气象观测表明,下击暴流的风暴中心是移动的,风暴的移动会对风场特征产生重要影响。为研究风暴移动对下击暴流风场特性的影响,基于计算流体动力学方法建立考虑移动效应的下击暴流数值模型,并通过可移动喷口的冲击射流试验对数值模拟结果进行了验证。结果表明:移动下击暴流风场在风暴中心前缘存在较大环涡,形成弓形分布的极值风速区域,最大水平风速出现在距离风暴中心r=1. 0Djet(Djet为喷口直径)左右,极值风速可达1. 5Vjet(Vjet为射流速度);风暴后方水平风速被减弱,最大风速出现在r=1. 5Djet附近,极值风速约为0. 8Vjet。近地面竖向风速随高度的增大而增大,受风暴移动的影响,在风暴中心区域,竖向风速向风暴移动方向一侧倾斜;在风暴中心区域以外,竖向风速主要由环涡引起,较大竖向风速主要分布于风暴中心后方以及风暴中心前方1. 0Djet^2. 0Djet的区域。风暴的移动导致风场中测点风速和风向随时间变化显著。Meteorological observation shows that the storm center of downburst moves,and the movement of the storm has an important influence on the characteristics of wind field. In order to study the effect of storm movement on the characteristics of wind field,a numerical model of downburst considering the moving effect was established based on computational fluid dynamics method,and numerical simulation results were verified by impinging jet test of movable nozzle. The results show that there is a large ring vortex in the front of the storm center of downburst wind field,which forms an extreme wind speed area of the bow distribution. The maximum horizontal wind speed occurs at r = 1. 0 Djet (Djetdenotes nozzle diameter),with the maximum wind speed being up to 1. 5 Vjet (Vjetdenotes jet velocity). The horizontal wind velocity behind the storm is weakened,the maximum wind speed occurs near r = 1. 5 Djet,and the extreme wind speed is about 0. 8 Vjet. The vertical wind speed of the near-ground region increases with the height,and the vertical wind speed is inclined to one side of the storm moving direction in the central area of the storm. Outside the storm central area,the vertical wind speed is mainly caused by the ring vortex. The larger vertical wind speed is mainly distributed behind the storm center and the area where r = 1. 0 Djet~ 2. 0 Djetin front of the storm center. The movement of the storm results in significant changes in wind speed and wind direction of measuring points in the wind field with time.

关 键 词：移动下击暴流 风暴移动 冲击射流试验 大涡模拟 风场特性 

分 类 号：TU312.1[建筑科学—结构工程] TU317.1