Journal article
Comparison of turbulent boundary layers over smooth and rough surfaces up to high Reynolds numbers
DT Squire, C Morrill-Winter, N Hutchins, MP Schultz, JC Klewicki, I Marusic
Journal of Fluid Mechanics | CAMBRIDGE UNIV PRESS | Published : 2016
DOI: 10.1017/jfm.2016.196
Abstract
Turbulent boundary layer measurements above a smooth wall and sandpaper roughness are presented across a wide range of friction Reynolds numbers, δ+99, and equivalent sand grain roughness Reynolds numbers, k+s (smooth wall: 2020 ≤ δ+99 ≤ 21 430, rough wall: 2890 ≤ δ+99 ≤ 29 900; 22 ≤ k+s ≤ 155; and 28 ≤ δ+99=k+s ≤ 199). For the rough-wall measurements, the mean wall shear stress is determined using a floating element drag balance. All smooth- and rough-wall data exhibit, over an inertial sublayer, regions of logarithmic dependence in the mean velocity and streamwise velocity variance. These logarithmic slopes are apparently the same between smooth and rough walls, indicating similar dynamics..
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Funding Acknowledgements
The authors wish to thank the Australian Research Council for the financial support of this research. M.P.S. would like to thank the U.S. Office of Naval Research for supporting his sabbatical visit to the University of Melbourne.