基于南海定点观测数据的强风场特性研究

Filed measurement of characteristics of strong wind loads on offshore structure in South China Sea

为了满足我国海洋工程抗风设计需求,在南海某海洋平台定点开展了原型测量工作。通过对海面上82 m和29 m两处开展实测工作,获得了冬季寒潮和超强台风"尤特"影响下的风场现场实测数据。利用非平稳过程分析方法对两类强风过程的脉动风分量、湍流强度、阵风因子、湍流积分尺度和脉动风谱等风场特性进行了分析。验证了脉动风分布的高斯性,给出了湍流强度与阵风因子的非线性拟合参数,分析了不同高度处风场特性剖面变化规律,证明了脉动风实测谱与Von Karman经验谱的良好拟合关系。

In order to satisfy wind resistant design demands of offshore structure in South China Sea,field measurement is implemented on a floating platform. Two anemometers are installed at the height of 82 m and 29 m to record wind speed and direction. Prototype data obtained during a cold wave period and typhoon ＂Utor＂are chosen as sample data for analysis. Characteristics of wind like fluctuating wind,turbulence intensity,gust factor,integral scale of turbulence and spectrum are analyzed by using nonstationary wind speed model. It is proved that the probability density function of fluctuation wind speed follows Gaussian distribution and Von Karman spectrum fits the measurement spectrum best. Parameters of empirical formulas,which describe relationships between turbulence intensity and gust factor,and wind speeds at different heights,are also obtained.