Imperial College London
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Emeritus ProfessorMichaelLeschziner

Faculty of Engineering, Department of Aeronautics

Emeritus Professor
 
 
 
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Contact

 

+44 (0)20 7594 5061mike.leschziner Website

 
 
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Location

 

CAGB317ACity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Agostini:2017:10.1103/PhysRevFluids.2.014603,
author = {Agostini, L and Leschziner, M},
doi = {10.1103/PhysRevFluids.2.014603},
journal = {Physical Review Fluids},
title = {Spectral analysis of near-wall turbulence in channel flow at Re-tau=4200 with emphasis on the attached-eddy hypothesis},
url = {http://dx.doi.org/10.1103/PhysRevFluids.2.014603},
volume = {2},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Direct numerical simulation data for channel flow at a friction Reynolds number of 4200, generated by Lozano-Durán and Jiménez [J. Fluid Mech. 759, 432 (2014)], are used to examine the properties of near-wall turbulence within subranges of eddy-length scale. Attention is primarily focused on the intermediate layer (mesolayer) covering the logarithmic velocity region within the range of wall-scaled wall-normal distance of 80–1500. The examination is based on a number of statistical properties, including premultiplied and compensated spectra, the premultiplied derivative of the second-order structure function, and three scalar parameters that characterize the anisotropic or isotropic state of the various length-scale subranges. This analysis leads to the delineation of three regions within the map of wall-normal-wise premultiplied spectra, each characterized by distinct turbulence properties. A question of particular interest is whether the Townsend-Perry attached-eddy hypothesis (AEH) can be shown to be valid across the entire mesolayer, in contrast to the usual focus on the outer portion of the logarithmic-velocity layer at high Reynolds numbers, which is populated with very-large-scale motions. This question is addressed by reference to properties in the premultiplied scalewise derivative of the second-order structure function (PMDS2) and joint probability density functions of streamwise-velocity fluctuations and their streamwise and spanwise derivatives. This examination provides evidence, based primarily on the existence of a plateau region in the PMDS2, for the qualified validity of the AEH right down the lower limit of the logarithmic velocity range.
AU  - Agostini,L
AU  - Leschziner,M
DO  - 10.1103/PhysRevFluids.2.014603
PY  - 2017///
SN  - 2469-990X
TI  - Spectral analysis of near-wall turbulence in channel flow at Re-tau=4200 with emphasis on the attached-eddy hypothesis
T2  - Physical Review Fluids
UR  - http://dx.doi.org/10.1103/PhysRevFluids.2.014603
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000393752800001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/53743
VL  - 2
ER  -
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