基于台风“梅花”的近地层湍流积分尺度实测分析

Field Measurements About Integral Scales of Near-ground Turbulence During Typhoon 'Muifa'

基于10,20和40m高度处台风"梅花"影响下的上海浦东地区近地风现场实测数据,分析了湍流积分尺度随平均风速、观测高度及平均时距的变化规律.结果表明:湍流积分尺度Lux,Lvx和Lxw会随平均风速和实测高度的增大而增大;10,20和40m高度处,湍流积分尺度均值Lux∶Lvx∶Lxw分别为1∶0.54∶0.07、1∶0.65∶0.11和1∶0.73∶0.1;相同高度处,Lux和Lvx随平均时距的增大而增大,而Lxw受平均时距的影响较小;湍流积分尺度Lxw在不同高度之间的相关系数整体上较Lux和Lvx偏小.

Variation of turbulence integral scales with mean wind speed, observation height and average time interval are analyzed based on the long time field measured data recorded respectively at 10, 20 and 40 meters above the ground in Pudong New Area of Shanghai during typhoon ＇Muifa＇. The results show that turbulence integral scales L~, L~ and L~ increase with mean wind speed and observation height. The ratios of the turbulence scale among the turbulence components averaged for all 10 min data are 1 ： 0.54 ： 0.07, 1 ： 0.65 ： 0.11 and 1 ： 0.73 ： 0.1 respectively at 10 m, 20 m and 40 m. At the same level,both of Luux and Lux increase with average time interval, but Lwx almost remains constant. The correlation coefficients of the vertical scales at two levels are much lower than those of the horizontal scales.