Periodicity of large-scale coherence in turbulent boundary layers
CM de Silva, D Chandran, R Baidya, N Hutchins, I Marusic
International Journal of Heat and Fluid Flow | Australasian Fluid Mechanics Society | Published : 2020
This study examines the pronounced periodicity of large-scale coherent structures in turbulent boundary layers, which are of the order of the boundary layer thickness and reside in the logarithmic and wake regions. To this end, a series of multi-camera planar particle image velocimetry (PIV) measurements are conducted in a streamwise-spanwise and streamwise-wall normal arrangements at a friction Reynolds number of Reτ ≈ 2500. The experiments are configured to capture velocity fields that cover a streamwise extent in excess of 15 boundary layer thicknesses. Preliminary observations of the vector fields reveal large-scale streamwise and spanwise organisation instantaneously, which is often los..View full abstract
The authors gratefully acknowledge the financial support of the Australian Research Council.