强风环境非平稳风速模型及应用

提出了强风环境非平稳风速分析模型。该模型将风速记录分解为时变平均风和零均值平稳脉动风分量两部分,给出了经验模型法确定时变平均风的步骤并重新定义了风特性参数的计算公式。分别采用非平稳和平稳风速模型进行了1 851小时实测强风资料的风特性参数计算并做了对比分析。结果显示非平稳模型计算得到的紊流强度和积分尺度较平稳模型小,而平均风速及相干函数的衰减系数则相当接近,非平稳模型较平稳模型更适合描述强风特性。

Nonstatioanry Wind Speed Model and Its Application in Strong Winds

A new wind model is proposed in this paper to analyze nonstationary wind data collected during strong winds. In the new model,the longitudinal wind speed is modeled as a deterministic time-varying mean wind speed plus a zero-mean stationary random process for longitudinal turbulent wind components. Formula for determining wind parameters is modified accordingly. The time-varying mean wind speed can be directly extracted from the original records by the empirical mode decomposition method. Using filed measured wind records of 1851-hour long,comparisons are made between the wind parameters obtained from two models including hourly mean wind speed, turbulence intensity, wind spectrum and integral length scale, root coherence function and probability density function. The results demonstrate that the nonstationary wind model appears to be more appropriate than the conventional stationary wind speed model for characterizing turbulent winds of one-hour duration.