摘要
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 intermittency from that in a symmetric flow. It is also shown that the intermittency property of the streamwise fluctuations is different from that of vertical fluctuations, and the intermittency 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.
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 intermittency from that in a symmetric flow. It is also shown that the intermittency property of the streamwise fluctuations is different from that of vertical fluctuations, and the intermittency 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.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina (Nos.1 0 2 72 0 71and1 0 472 0 63 )
