Coherent motions in the turbulent boundary layer and their relation to the large-scale structures in the intermittent region are investigated experimentally. Using conditional sampling technique, we have shown that a coherent motion is a pair of counter-rotating fluid motions. These coherent motions of various sizes take place in the turbulent boundary layer. Most of them are short and are found only near the wall, but some are tall enough to reach the outer edge of the boundary layer. The turbulent bulges of the intermittent region are formed by these tall coherent motions.
ASJC Scopus subject areas
- Mechanical Engineering
- Physics and Astronomy(all)
- Fluid Flow and Transfer Processes