台风“蝴蝶”非平稳风特性研究

Research on Non-stationary Wind Characteristics of Typhoon“Butterfly”

通过琼州海峡地区风速观测系统记录的台风“蝴蝶”三维风场实测数据,分析了台风“蝴蝶”的风场特性;基于非平稳模型理论,利用经验模态分解、分离趋势项,对台风时变平均风速与风向、湍流强度、阵风因子、湍流积分尺度和脉动风速功率谱等风特性开展了研究。结果表明:三维湍流强度比值比规范要求的偏小;顺风向湍流强度、阵风因子、湍流积分尺度大于横向与竖向,阵风因子与湍流强度的非线性拟合比Ishizaki、Choi和Cao取值偏低;脉动风速紊流功率密度斜率近似符合Kolmogrove“-5/3律”;实测顺风向脉动风速功率谱与Davenport经验谱在低频段符合较好,但在高频段有一定偏差。

In this paper,the wind field characteristics of typhoon“Butterfly”are analyzed,which is recorded by a3D wind field observation system in Qiongzhou Strait area;Based on the theory of non-stationary model,the wind characteristics of typhoon,such as time-varying average wind speed and direction,turbulence intensity,gust factor,turbulence integral scale and wind power spectrum,are studied by empirical mode decomposition and separation trends.The results show that the ratio of 3D turbulence intensity is smaller than the specification;The longitudinal turbulence intensity,gust factor and turbulence integral scale are larger than both of the transverse and vertical ones,and the nonlinear fitting values of gust factor and turbulence intensity are lower than the results of Ishizaki,Choi and Cao;The slope of fluctuating wind power spectrum approximately satisfy the Kolmogrove’s“-5/3 law”;In low frequency band,the longitudinal fluctuating wind power spectrum fits well with the Davenport’s experience spectrum.But there is a certain deviation in high frequency band.