Imperial College London

ProfessorSergeiChernyshenko

Faculty of EngineeringDepartment of Aeronautics

Chair in Aerodynamics
 
 
 
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Contact

 

+44 (0)20 7594 5548s.chernyshenko Website

 
 
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Location

 

211aCity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Ghebali:10.1063/1.5003617,
author = {Ghebali, S and Chernyshenko, SI and Leschziner, MA},
doi = {10.1063/1.5003617},
journal = {Physics of Fluids},
pages = {105102--105102},
title = {Can large-scale oblique undulations on a solid wall reduce the turbulent drag?},
url = {http://dx.doi.org/10.1063/1.5003617},
volume = {29},
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Direct numerical simulations of fully-developed turbulent channel flows withwavy walls are undertaken. The wavy walls, skewed with respect to the mean flowdirection, are introduced as a means of emulating a Spatial Stokes Layer (SSL)induced by in-plane wall motion. The transverse shear strain above the wavywall is shown to be similar to that of a SSL, thereby affecting the turbulentflow, and leading to a reduction in the turbulent skin-friction drag. Thepressure- and friction-drag levels are carefully quantified for various flowconfigurations, exhibiting a combined maximum overall-drag reduction of about0.5%. The friction-drag reduction is shown to behave approximatelyquadratically for small wave slopes and then linearly for higher slopes, whilstthe pressure-drag penalty increases quadratically. Unlike in the SSL case,there is a region of increased turbulence production over a portion of thewall, above the leeward side of the wave, thus giving rise to a local increasein dissipation. The transverse shear-strain layer is shown to be approximatelyReynolds-number independent when the wave geometry is scaled in wall units.
AU - Ghebali,S
AU - Chernyshenko,SI
AU - Leschziner,MA
DO - 10.1063/1.5003617
EP - 105102
SP - 105102
TI - Can large-scale oblique undulations on a solid wall reduce the turbulent drag?
T2 - Physics of Fluids
UR - http://dx.doi.org/10.1063/1.5003617
UR - http://arxiv.org/abs/1705.01989v2
UR - http://hdl.handle.net/10044/1/53594
VL - 29
ER -