Abstract
Turbulent flow over a “dynamically rough” wall is modeled by considering time-dependent velocity perturbations in the streamwise and wall-normal directions imposed at the wall, a crude linearization. Analysis of the linearized Navier-Stokes operator is performed to select roughness parameters that are predicted to lead to a large disturbance amplification in the body of the flow. Direct numerical simulations of turbulent channel flow at Re τ ∼ 500 with three different roughness amplitudes, a +, indicate that for \({a}^{+}\,=\,10\) the response of the flow approximates this predicted form, including the development of a significant spanwise velocity component. The turbulence characteristics, as a function of amplitude, are hypothesized to offer insight of relevance to the static roughness problem.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
O. Flores, J. Jiménez, Effect of wall-boundary disturbances on turbulent channel flows. J. Fluid Mech. 566, 357–376 (2006).
M. Gaster, C.E. Grosch, T.L. Jackson, The velocity field created by a shallow bump in a boundary layer. Phys. Fluids 6(9), 3079–3085 (1994).
B.J. McKeon, A model for “dynamic roughness” in turbulent channel flow, in Center for Turbulence Resaerch, Proceedings of the Summer Program, 2008.
R. Mejia-Alvarez, K.T. Christensen, Flow of turbulent boundary layers over low-order representations of irregular surface roughness. AIAA Paper, AIAA 2009-3681, (2009).
P. Orlandi, S. Leonardi, R. Tuzi, R.A. Antonia, Direct numerical simulation of turbulent channel flow with wall velocity disturbances. Phys. Fluids 15(12), 3587–3601 (2003).
Acknowledgements
The author wishes to acknowledge Javier Jiménez for generously permitting the use of the DNS code and for useful conversations and ideas, and the support of a CTR Summer Program fellowship during the summer of 2008.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 Springer Science+Business Media B.V.
About this paper
Cite this paper
McKeon, B.J. (2010). Turbulent Channel Flow over Model “Dynamic” Roughness. In: Nickels, T. (eds) IUTAM Symposium on The Physics of Wall-Bounded Turbulent Flows on Rough Walls. IUTAM Bookseries, vol 22. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-9631-9_12
Download citation
DOI: https://doi.org/10.1007/978-90-481-9631-9_12
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-9630-2
Online ISBN: 978-90-481-9631-9
eBook Packages: EngineeringEngineering (R0)