Some characteristics of the coherent structures in turbulent boundary layers

  • Davide Poggi
Conference paper
Part of the Fluid Mechanics and Its Applications book series (FMIA, volume 71)


The present work describes the results of an experimental study about the kinematics of the coherent structures in an open channel flow. The coherent events, detected in the near-wall region, are analysed by an original method based on conditional-sampling. Using simple kinematic characteristics occurring during the bursting events the coherent structures are grouped into several clusters obtaining a substantial improvement over the classical conditional average. In this way different kinds of coherent structures are distinguished, and probably ascribed to different phases of the same group of coherent structures. In particular, we show experimental evidence supporting the hypothesis about coherent packets of hairpin vortices formulated by Zhou et al. 1999 even at high Reynolds number. This analysis of the near-wall region is realised by means of a new experimental technique which allows an accurate measurement of the streamwise and wall-normal turbulent velocity components (u and v respectively) in the flow field very close to the wall.


Reynolds Stress Turbulent Boundary Layer Coherent Structure Secondary Peak Open Channel Flow 
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  1. Adrian, R. J., Meinhart, C. D. and Tomkins, C. D. (2000). Vortex organization in the outer region of the turbulent boundary layer. J. Fluid Mech., 422, 1–54.CrossRefMathSciNetADSzbMATHGoogle Scholar
  2. Jeong, J., Hussain, F., Schoppa, W. and Kim, J. 1997 Coherent structure near the wall in a turbulent channel flow. J Fluid Mech.332, 185–214.ADSzbMATHGoogle Scholar
  3. Jiménez, J. & Pinelli, A. 1999 The autonomous cycle of near-wall turbulence. J. Fluid Mech.225, 213–241.CrossRefGoogle Scholar
  4. Lu, S. S. & Willmarth, W. W. 1973 Measurements of the structure of the Reynolds stress in a turbulent boundary layer. J Fluid Mech. 60, 481–511.ADSCrossRefGoogle Scholar
  5. Nakagawa, H. & Nezu, I. 1981 Structures of space-time correlations of bursting phenomena on open-channel flow. J Fluid Mech.104, 1–22.ADSCrossRefGoogle Scholar
  6. Poggi, D., Porporato, A. and Ridolfi, L. An experimental contribution to near wall measurements by means of a special laser Doppler anemometry technique. Exp. Fluids.32, 366–375.Google Scholar
  7. Poggi, D.; Porporato, A.; Ridolfi, L. Experimental investigation of the near-wall flow field during bursting events, in Ed World Scientific Publishing, SingaporeIn press, FMTM2001, December 4–6, 2001, Tokyo, Japan.Google Scholar
  8. Robinson, S. K. 1991 Coherent motion in the turbulent boundary layer. Ann. Rev. Fluid Mech.23, 601–622.CrossRefADSGoogle Scholar
  9. Smith, C. R. & Walker, J. D. A. 1997 Sustaining mechanisms of turbulent boundary layers: The role of vortex development and interactions. Panton 13–47.Google Scholar
  10. Zhou, J., Adrian, R. J., Balachandar, S. and Kendall, T. M. 1999 Mechanisms for generating coherent packets of hairpin vortices in channel flow. J. Fluid Mech., 387, 353–396.CrossRefMathSciNetADSzbMATHGoogle Scholar
  11. Yuan, Y. M. & Mokhtarzadeh-Dehghan M. R. 1994 A comparison of conditional-sampling methods used to detect coherent structures in turbulent boundary layers. Phys. Fluids6, 2038–2057.CrossRefADSGoogle Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Davide Poggi
    • 1
  1. 1.Dipartimento di IdraulicaTrasporti ed Infrastrutture Civili, Politecnico di TorinoTorinoItaly

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