完全发展的非对称槽道湍流的标度指数研究

以子波变换为分析工具，研究了完全发展的非对称槽道湍流的局部标度指数和整体标度指数．其中整体标度指数通过正交子波和广义自相似定律得到，其结果表明非对称槽道流动呈现出与对称槽道流极为不同的间歇性，随着壁面距离的增大，横向脉动速度与流向脉动速度呈现出不同的间歇性，而且间歇性并非一直减弱．另外，比较分析了几种不同方法得到的局部标度指数，发现连续子波方法计算局部标度指数并不可靠，对于湍流研究中出现的负局部标度指数的情况需要慎重考虑．

Scaling Exponents in Fully Developed Asymmetric Channel Flow

Wavelet analysis is applied to study the global and local scaling exponents in fully developed asymmetric channel flow. Global exponents are calculated by orthogonal wavelets and Extended Scaling Similarity(ESS). The results show that the flow in an asymmetric channel flow exhibits different characteristics of intermittence from that in a symmetric flow. It is also shown that the intermittence property of the streamwise fluctuations is different from that of vertical fluctuations, and the intermittence does not decay with the increase of the distance from the wall. In addition, the Continuous Wavelet Transform(CWT) method is found to be unreliable to calculate the local scaling components. Finally, it is pointed out that the existence and the significance of negative local scaling components need further study.