Multi-scale coherent structures in turbulent boundary layer detected by locally averaged velocity structure functions

作者：Liu JH; Jiang N^*; Wang ZD; Shu W

来源：Applied Mathematics and Mechanics, 2005, 26(4): 495-504.

DOI：10.1007/bf02465389

• turbulent boundary layer
• coherent structure
• flatness factor
• intermittency
• locally averaged velocity structure function

The time sequence of longitudinal velocity component at different vertical locations in turbulent boundary layer was finely measured in a wind tunnel. The concept of coarse-grained velocity structure functions, which describes the relative. motions of straining and compressing for multi-scale eddy structures in turbulent flows, was put forward based on the theory of locally multi-scale average: Based on the consistency between coarse-grained velocity structure function and Harr wavelet transformation, detecting method was presented, by which the coherent structures and their intermittency was identified by multi-scale flatness factor calculated by locally average structure function. Phase-Averaged evolution course for multi-scale coherent eddy structures in wall turbulence. were extracted by this conditional sampling to educe scheme. The dynamics course of multi-scale coherent eddy structures and their effects on statistics of turbulent flows were studied.

• 出版日期2005-4
• 单位天津大学