Documentation of the role of large-scale structures in the bursting process in turbulent boundary layers

Författare: Vinuesa, R., Hites, M. H., Wark, C., Nagib, H.M.
Dokumenttyp: Artikel
Tillstånd: Publicerad
Tidskrift: Physics of Fluids
Volym: 27   105107
År: 2015


The scaling of the bursting frequency with Reynolds number is investigated experimentally by means of hot-wire measurements in turbulent boundary layers over the range 1; 580 < Re < 23; 700. Bursting events are detected by means of the u-level technique, and the eect of ltering and the choice of the threshold are also assessed. We nd that the inner scaling produces excellent collapse of the high-pass ltered data in the buer and log regions, regardless of the cut-o frequency and the threshold. This is due to the fact that the high-pass lter attenuates the low frequency component of the streamwise velocity signal, which is associated with large-scale structures in the flow. On the other hand, the bursting frequency scales with outer variables when the time-series is low-pass ltered with very low cut-o frequencies, highlighting the connection between bursting phenomena and the outer flow.