Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 10, 2011 | Published
Journal Article Open

Interactions within the turbulent boundary layer at high Reynolds number

Abstract

Simultaneous streamwise velocity measurements across the vertical direction obtained in the atmospheric surface layer (Re_τ ≃ 5 × 10^5) under near thermally neutral conditions are used to outline and quantify interactions between the scales of turbulence, from the very-large-scale motions to the dissipative scales. Results from conditioned spectra, joint probability density functions and conditional averages show that the signature of very-large-scale oscillations can be found across the whole wall region and that these scales interact with the near-wall turbulence from the energy-containing eddies to the dissipative scales, most strongly in a layer close to the wall, z^+ ≲ 10^3. The scale separation achievable in the atmospheric surface layer appears to be a key difference from the low-Reynolds-number picture, in which structures attached to the wall are known to extend through the full wall-normal extent of the boundary layer. A phenomenological picture of very-large-scale motions coexisting and interacting with structures from the hairpin paradigm is provided here for the high-Reynolds-number case. In particular, it is inferred that the hairpin-packet conceptual model may not be exhaustively representative of the whole wall region, but only of a near-wall layer of z^+ = O(10^3), where scale interactions are mostly confined.

Additional Information

© 2011 Cambridge University Press. Received 8 December 2009; revised 25 August 2010; accepted 25 August 2010. The support of ONR grant N00014-08-1-0897 (programme manager Ron Joslin) is gratefully acknowledged.

Attached Files

Published - Guala2011p12811J_Fluid_Mech.pdf

Files

Guala2011p12811J_Fluid_Mech.pdf
Files (4.8 MB)
Name Size Download all
md5:2ff6f6700254d189074ce8e07d97cab7
4.8 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023