华东地区近地台风不同时距特性研究

基于2011年两次不同强度台风“米雷”和“梅花”影响下上海浦东国际机场附近沿海地区40m高测风塔获得的近地风实测数据，分析了不同时距下湍流度、阵风因子、峰值因子以及湍流积分尺度等风参数特性。研究表明：湍流度均值随时距的增大而减小且与Durst的研究结果一致，风速较小的“米雷”湍流度均值比风速较大的“梅花”的大；阵风因子均值在10m以上实测结果与美国规范ASCE/SEI 7-10曲线接近，而10 m高度处的实测值偏大；峰值因子均值随时距增大而减小，但受实测高度和风速变化的影响较小；台风“米雷”峰值因子均值在时距大于100 s后略大于“梅花”，但总体上与Durst的研究结果一致。在各时距下台风“米雷”纵向、横向和竖向湍流积分尺度均值比“梅花”的大，两次台风的纵向湍流尺度在10 m高度处1 min~1 h时距的变化范围分别为27~267 m和27~205 m，当时距足够大时横向积分尺度会大于纵向值。

Field measurement of typhoon winds near ground characteristics at different segment lengths in East China

In this research, the wind data was measured from a tower of 40m in height during the mild typhoon ‘Meari’ and ultra strong typhoon ‘Muifa’ near Shanghai Pudong International Airport by the East China Sea. The characteristics of turbulence intensity, gust factors, peak factor and turbulence integral scale for various segment lengths were analyzed in detail. It shows that turbulence intensity decreases with the increase of segment lengths and agrees well with Durst’s results. As expected, the value measured from the mild typhoon ‘Meari’ is larger than that of the ultra strong typhoon ‘Muifa’. Gust factors measured at 10m are larger than those of the above heights which agree well with ASCE/SEI 7-10. The peak factor also decreases with the increase of segment lengths and agrees well with those proposed by Durst. For segment lengths more than 100 s, the value of peak factor measured from ‘Meari’ is larger than that of ‘Muifa’. Furthermore, as the segment length increases, the turbulence integral scale will be larger, especially the lateral length scale will be larger than that of the longitudinal value, and all its components measured from ‘Meari’ are larger than those of ‘Muifa’ for various segment lengths. At a 10m observation height, for instance, estimates of L_u vary from 27 m to 267 m for ‘Meari’ and 27 m to 205 m for ‘Muifa’, respectively.