移动型下击暴流及其作用下高层建筑风荷载的数值模拟  

THE NUMERICAL SIMULATION OF MOVING DOWNBURSTS AND THEIR INDUCED WIND LOAD ON HIGH-RISE BUILDINGS

作　　者：李艺[1] 黄国庆[1,2] 程旭 赵丽娜[3] LI Yi;HUANG Guo-qing;CHENG Xu;ZHAO Li-na(Department of Civil Engineering,Southwest Jiaotong University,Chengdu 610000,China;Department of Civil Engineering,Chongqing University,Chongqing 400000,China;Ziyang City Municipal Bureau of Natural Land and Resources,Ziyang 641300,China)

机构地区：[1]西南交通大学土木工程系,成都610000 [2]重庆大学土木工程系,重庆400000 [3]资阳市自然资源和规划局,资阳641300

出　　处：《工程力学》2020年第3期176-187,共12页Engineering Mechanics

基　　金：国家自然科学基金项目(51578471;51778546)。

摘　　要：下击暴流造成了大量的输电线塔、风机等结构的破坏,对其风场及其引起的结构风荷载研究非常迫切。该文基于RANS,利用SST k-ω湍流模型模拟了下击暴流风速特性及其作用下高层建筑的风荷载。对静止型下击暴流及其作用下高层建筑的风荷载进行了三维定常数值模拟,并将模拟结果与风洞试验结果相对比,结果表明:所建立的CFD计算模型能较好地模拟下击暴流及其作用下高层建筑的风荷载。借助于滑移网格技术对移动型下击暴流进行数值模拟,探究了相应的下击暴流风场及其对位于射流口中心移动路径上的高层建筑的风荷载。将该文模拟得到的移动型下击暴流径向风剖面与实测结果以及其他学者模拟结果相比较,吻合度较高,验证了凭借滑移网格技术能逼真地模拟出下击暴流的风场特性及其作用下高层建筑的风荷载。将静止型和移动型下击暴流的风场特性及其对建筑物的风压作用进行详细对比,研究结果表明:射流口的移动增强了运动方向的径向风速,减小了负方向的风速,并增大了建筑物表面的风压系数,这在结构设计中应予以考虑。The downbursts cause damage to the structures of transmission line towers,wind turbines and so on.It is urgent to study the wind field and the downburst-induced structural wind load.Based on the RANS,computational fluid dynamics(CFD)numerical simulations using the SST k-ω turbulence model were conducted to study the wind field characteristics of downbursts and the wind load on high-rise buildings under the downbursts.A three-dimensional steady-state numerical simulation of a static downburst and the wind load on high-rise buildings under the downburst was carried out.The simulation results were compared with wind tunnel tests.The results show that the established CFD computational model can well simulate the downbursts and the wind load on high-rise buildings.Sliding grid is a technique that can accurately solve multi-motion reference system problems.The numerical simulation of moving downbursts using the sliding grid technology was conducted to study the corresponding downburst wind field and the wind load on high-rise buildings located on the moving path of a jet center.Comparing the radial wind profile of the moving downburst obtained with the measured results and the simulation results by other scholars.It is verified that the wind field characteristics of moving downbursts and the downburst-induced wind load on buildings can be realistically simulated with the aid of the sliding grid technique.A detailed comparison was made between the static and the moving downbursts in terms of wind field characteristics and the wind load on buildings.The results show that the overall movement of the jet port increases the radial wind speed in the moving direction,reduces the wind speed in the negative direction,and increases the pressure coefficient on the building surface.These effects should be considered in the structural design.

关 键 词：结构工程 移动下击暴流 CFD 风场特性 风荷载 增强效应 

分 类 号：TU973.32[建筑科学—结构工程]