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On the Size of the Eddies in the Outer Turbulent Wall Layer: Evidence from Velocity Spectra

  • Sergio PirozzoliEmail author
Conference paper
Part of the ERCOFTAC Series book series (ERCO, volume 23)

Abstract

The scaling of size of the momentum-bearing eddies in wall-parallel planes in the outer part of turbulent wall layers is analyzed, by examining spectra of the fluctuating velocities taken from direct numerical simulations and experiments. For all flows under scrutiny the normalized spectra highlight growth of the eddies size with the wall distance. The results indicate the capability of a modified mixing length (Pirozzoli, J Fluid Mech 702:521–532, 2012 [1]) of accounting with greater precision for the wall-normal variation of the size of the eddies bearing streamwise momentum. This observation can be explained by assuming that outer layer momentum streaks (superstructures) spread under the collective action of the other eddies, which impart a (nearly) uniform eddy diffusivity throughout the outer wall layer.

Keywords

Wall-bounded flows Turbulence Coherent structures 

Notes

Acknowledgments

I acknowledge that some results in this paper have been achieved using the PRACE Research Infrastructure resource JUGENE based at the Forschungszentrum Jülich (FZJ) in Jülich, Germany. Thanks are also due to Sean C.C. Bailey, Alexander J. Smits, Nicholas Hutchins, and Ivan Marusic, for providing experimental data and other useful information.

References

  1. 1.
    S. Pirozzoli, J. Fluid Mech. 702, 521–532 (2012)zbMATHCrossRefGoogle Scholar
  2. 2.
    Y. Mizuno, J. Jiménez, Phys. Fluids 23, 085112 (2011)zbMATHCrossRefGoogle Scholar
  3. 3.
    S. Pirozzoli, M. Bernardini, J. Fluid Mech. 688, 120–168 (2011)zbMATHMathSciNetCrossRefGoogle Scholar
  4. 4.
    S. Pirozzoli, M. Bernardini, Phys. Fluids 25, 021704 (2013)CrossRefGoogle Scholar
  5. 5.
    S. Pirozzoli, M. Bernardini, P. Orlandi, J. Fluid Mech. 680, 534–563 (2011)zbMATHCrossRefGoogle Scholar
  6. 6.
    M. Bernardini, S. Pirozzoli, P. Orlandi, J. Fluid Mech. (2013). Under reviewGoogle Scholar
  7. 7.
    J.C. del Álamo, J. Jiménez, P. Zandonade, R.D. Moser, J. Fluid Mech. 500, 135 (2004)zbMATHCrossRefGoogle Scholar
  8. 8.
    J. Jiménez, R. Moser, Philos. Trans. R. Soc. Lond. A 365, 715 (2007)zbMATHCrossRefGoogle Scholar
  9. 9.
    N. Hutchins, I. Marusic, J. Fluid Mech. 579, 1 (2007)zbMATHCrossRefGoogle Scholar
  10. 10.
    N. Hutchins, W.T. Hambleton, I. Marusic, J. Fluid Mech. 541, 21 (2005)CrossRefGoogle Scholar
  11. 11.
    S. Bailey, A. Smits, J. Fluid Mech. 651, 339 (2010)zbMATHCrossRefGoogle Scholar
  12. 12.
    J. Jiménez, Annu. Rev. Fluid Mech. 44, 27 (2012)CrossRefGoogle Scholar
  13. 13.
    J. Monty, J. Stewart, R. Williams, M. Chong, J. Fluid Mech. 589, 147 (2007)zbMATHCrossRefGoogle Scholar
  14. 14.
    S.I. Chernyshenko, M.F. Baig, J. Fluid Mech. 544, 99 (2005)zbMATHMathSciNetCrossRefGoogle Scholar
  15. 15.
    A. Townsend, The Structure of Turbulent Shear Flow, 2nd edn. (Cambridge University Press, Cambridge, 1976)zbMATHGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Dipartimento di Ingegneria Meccanica E AerospazialeUniversità di Roma ‘La Sapienza’RomeItaly

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