Imperial College London
Alternate

Dr. Yongyun Hwang

Faculty of Engineering, Department of Aeronautics

Reader in Fluid Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 5078y.hwang

 
 
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Location

 

337City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Hwang:2020:10.1017/jfm.2020.730,
author = {Hwang, Y and Myoungkyu, L},
doi = {10.1017/jfm.2020.730},
journal = {Journal of Fluid Mechanics},
pages = {R6--1--R6--11},
title = {The mean logarithm emerges with self-similar energetics},
url = {http://dx.doi.org/10.1017/jfm.2020.730},
volume = {903},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The attached eddy hypothesis of Townsend (The structure of turbulent shear flow, 1956,Cambridge U. Press) states that the logarithmic mean velocity would admit self-similarenergy-containing  eddies  which  scales  with  the  distance  from  the  wall.  Over  the  pastdecade, there has been significant amount of evidence supporting the hypothesis, placingit  to  be  the  central  platform  for  the  statistical  description  of  the  general  organisationof  coherent  structures  in  wall-bounded  turbulent  shear  flows.  Nevertheless,  the  mostfundamental question, namely why the hypothesis has to be true, remains unansweredover many decades. Under the assumption that the integral length scale is proportionalto the distance from the wally, in the present study, we analytically demonstrate thatthe  mean  velocity  is  a  logarithmic  function  ofyif  and  only  if  the  energy  balance  atintegral  length  scale  is  self-similar  with  respect  toy,  providing  a  theoretical  groundfor  the  attached  eddy  hypothesis.  The  analysis  is  subsequently  verified  with  the  datafrom direct numerical simulation of incompressible channel flow at the friction ReynoldsnumberReτ'5200 (Lee & Moser,J. Fluid Mech., vol. 774, 2015, 395–415).
AU  - Hwang,Y
AU  - Myoungkyu,L
DO  - 10.1017/jfm.2020.730
EP  - 1
PY  - 2020///
SN  - 0022-1120
SP  - 6
TI  - The mean logarithm emerges with self-similar energetics
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2020.730
UR  - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/mean-logarithm-emerges-with-selfsimilar-energy-balance/2B1825CC85C0F0CA6D64D78E135ED648
UR  - http://hdl.handle.net/10044/1/82769
VL  - 903
ER  -
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