基于天气预报模式和大涡模拟的台风风场多尺度耦合数值模拟  

Multi-scale simulation of typhoon wind fields by coupling of weather research and forcasting model and large-eddy simulation

作　　者：黄铭枫[1] 孙建平 王义凡 楼文娟[1] HUANG Mingfeng;SUN Jianping;WANG Yifan;LOU Weijuan(Institute of Structural Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学建筑工程学院

出　　处：《建筑结构学报》2020年第2期63-70,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51578504,51838012)

摘　　要：结合2015年第1509号超强台风"灿鸿"期间在杭州九堡大桥的现场实测数据,基于WRF(weather research and forecasting)和LES(大涡模拟)的台风多尺度耦合数值模拟方法,重现了台风"灿鸿"的中小尺度发展演化过程,并对九堡大桥周边台风风场进行多尺度精细化模拟;以多项式插值的方式解决疏网格向密网格的背景风场要素降尺度耦合问题;最后通过大涡模拟获得了九堡大桥周边地区30 min瞬态台风风场数据。模拟得到的瞬态风速结果与实测数据在统计意义上较为吻合,表明WRF-LES耦合系统能实现从气象中尺度到建筑小尺度的多尺度数值模拟,有效地获取一次台风过程中目标区域的瞬态台风风场。NSRFG(narrowband synthesis random flow generator)方法生成的入口脉动风速适用于局部台风风场的LES计算,模拟所得风速功率谱与实测结果在低频段基本一致。Based on full-scale measurements on Hangzhou Jiubao Bridge during Typhoon Chan-hom in 2015,a multiscale coupled simulation method of WRF(weather research and forecast)and LES(large-eddy simulation)was developed to reproduce the evolution of Chan-hom in mesoscale and solve typhoon wind fields around Jiubao Bridge in refined micro-scale.The polynomial interpolation method was employed to implement a downscale scheme of meteorological variables from the coarse grid in WRF to the refined grid in LES.Half-hour time-varying typhoon wind fields around Jiubao Bridge were finally obtained by the LES coupled to the WRF model.The simulated turbulent wind velocities generally agree well with the observations in aspect of overall fluctuating trends,which indicates that multiscale numerical simulation from meteorological mesoscale to building scale can be achieved by coupling of WRF and LES,obtaining the transient typhoon wind flow field in target area during a typhoon event effectively.The inflow fluctuating wind velocity generated by NSRFG(narrowband synthesis random flow generator)method is suitable for the LES calculation of the local typhoon wind field,and the simulated wind velocity spectrum matches the measured data at low frequency.

关 键 词：台风近地风场 天气预报模式(WRF) 大涡模拟 多尺度耦合 数值模拟 

分 类 号：TU312.1[建筑科学—结构工程]