大气边界层剪切湍流统计特性的风洞实验及其层次相似律

Dynamic Property of Atmospheric Shear Turbulent Flow and Its Self-Similarity in the Wind Tunnel Experiment

对风洞模拟的大气边界层的剪切湍流场的速度脉动时间序列信号以及某一高度位置上的小波变换分解重构的信号进行了系统的统计分析。结果表明,在非均匀下垫面大气边界层的不同垂直高度上的信号,SheLeveque湍流层次相似律都成立,层次相似指数β和最高激发态的奇异标度指数γ随垂直高度的变化而变化,并给出不同尺度的分解重构信号的一些层次结构特点。

The time series of velocity fluctuation of the atmospheric turbulent boundary layer simulated in wind tunne are measured and statistically analyzed. The result shows that the She-Leveque hierarchical similarity law always holds water at the various vertical heights of the heterogeneous surface boundary layer. The hierarchical similarity exponent β and the most intermittent scaling exponent γ vary with the vertical heights. The decomposed and recomposed series by wavelet transformation at one height is analyzed, and some hierarchical structure characters in them are presented.