台风湍流积分尺度与脉动风速谱——基于实测数据的分析

Turbulence integral scale and fluctuation wind speed spectrum of typhoon:an analysis based on field measurements

基于4个台风过程中的长时间序列风速、风方向观测数据,分析研究了近地台风的湍流积分尺度和脉动风速谱等脉动特性。介绍了湍流积分尺度的几种常见的计算方法,基于实测台风数据,分析研究了台风过程中湍流积分尺度的变化以及不同计算方法的稳定性。根据实测数据计算了纵向脉动风速谱,并与Von-Karm an谱、Davenport谱、S im iu谱和Harris谱等经验谱进行了比较,给出了最适合描述台风纵向脉动风速谱的经验谱。还计算了横向脉动风速功率谱,并与基于各向同性湍流理论推导出的水平横向脉动风速谱进行了对比。

In this paper, the fluctuation characteristics of turbulence integral scale and wind speed spectra of near ground typhoon are studied based on the four sets of long time record of wind speed and wind direction during the passages of typhoon. Firstly, several calculation methods for turbulence integral scale are presented. Secondly, the variation of turbulence integral scale during the passage of typhoon, as well as the stabilization of the calculation methods are investigated. Then, the longitudinal fluctuation wind speed spectra are calculated and the comparison to the empirical spectra, such as the Von-karman spectrum, the Davenport spectrum, the Simiu spectrum and Harris spectrum, are implemented. The best one fitting to the field measurements is recommended. Finally, the lateral wind spectra are calculated, and the comparison to the spectrum derived from longitudinal wind spectrum based on isotropic turbulence theory is performed.