Thermophysics and Aeromechanics

, Volume 23, Issue 5, pp 657–666 | Cite as

Experimental investigation of wake evolution behind a couple of flat discs in a hydrochannel

  • I. V. NaumovEmail author
  • I. V. Litvinov
  • R. F. Mikkelsen
  • V. L. Okulov


The decay of a far wake and its turbulent fluctuations behind two thin discs of the same diameter D, oriented normal to the incident flow, have been studied using the Particle Image Velocimetry (PIV). The experimental study was carried out in a water flume (Re ≈ 2·105) with varying distances between the discs (L х = 4–8D) and their axes shift relative to each other (0, 0.5D and 1D). It is found that the velocity deficit behind two discs depends weakly on L x , and at L х > 40D, it becomes indistinguishable from the level of turbulent fluctuations of the incident flow. It is found that the decay of the average velocity deficit and its turbulent fluctuations in a wake of a tandem of discs can be described by the same analytical dependence with exponent–2/3 as for the wake decay of a single disc. However, at the same distance downstream, the value of deficit behind two discs is substantially higher than the corresponding value behind a single disc. Velocity fluctuations in a far wake behind a pair of discs depend weakly on longitudinal dimension L x , but at the same time, in contrast to the velocity deficit, their level does not differ significantly from the level of fluctuations behind a single disc.

Key words

wake behind a bluff body level of turbulence of the incident flow pair of discs velocity deficit Particle Image Velocimetry (PIV) 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M.M. Zdravkovich, Review of flow interference between two circular cylinders in various arrangements, Trans. ASME. J. Fluids Engng, 1977, Vol. 99, No. 4, P. 618–633.ADSCrossRefGoogle Scholar
  2. 2.
    F. Auteri, M. Belan, G. Gibertini, and D. Grassi, Normal flat plates in tandem: An experimental investigation, J. Wind Engng Ind. Aerodyn., 2008, Vol. 6, No. 96, P. 872–879.CrossRefGoogle Scholar
  3. 3.
    H. Hacışevki and A. Teimourian, Comparison of flow structures in the wake region of two similar normal flat plates in tandem and a square cylinder, Exp. Therm. Fluid Sci., 2015, Vol. 69, P. 169–177.CrossRefGoogle Scholar
  4. 4.
    F. Porté-Agel, Y.T. Wu, and C.H. Chen, Numerical study of the effects of wind direction on turbine wakes and power losses in a large wind farm, Energies, 2013, Vol. 6, No. 10, P. 5297–5313.CrossRefGoogle Scholar
  5. 5.
    X. Yang, S. Kang, and F. Sotiropoulos, Computational study and modeling of turbine spacing effects in infinite aligned wind farms, Physics of Fluids, 2012, Vol. 24, No. 11, P. 115107–1–115107-28.ADSCrossRefGoogle Scholar
  6. 6.
    S. Aubrun, S. Loyera, P.E. Hancock, and P. Hayden, Wind turbine wake properties: Comparison between a nonrotating simplified wind turbine model and a rotating model, J. Wind Engng Ind. Aerodyn., 2013, Vol. 120, P. 1–8.CrossRefGoogle Scholar
  7. 7.
    A. Roshko, On the wake and drag of bluff bodies, J. Aeronautical Sci., 1955, Vol. 2, P. 124–132.CrossRefzbMATHGoogle Scholar
  8. 8.
    J. Yang, M. Liu, G. Wu, W. Zhong, and X. Zhang, Numerical study on coherent structure behind a circular disk, J. Fluids Struct., 2014, Vol. 51, P. 172–188.ADSCrossRefGoogle Scholar
  9. 9.
    B.G. Novikov, Effect of small total pulse on development of a wake behind the self-propelled bodies, Thermophysics and Aeromechanics, 2009, Vol. 16, No. 4, P. 561–583.ADSCrossRefGoogle Scholar
  10. 10.
    P.B. Johansson, W.K. George, and M.J. Gourlay, Equilibrium similarity, effects of initial conditions and local Reynolds number on the axisymmetric wake, Phys. Fluids, 2003, Vol. 15, No. 3, P. 603–617.ADSMathSciNetCrossRefzbMATHGoogle Scholar
  11. 11.
    P.B. Johansson and W.K. George, The far downstream evolution of the high-Reynolds number axisymmetric wake behind a disk. Part 1. Single-point statistics, J. Fluid Mech., 2006, Vol. 555, P. 363–385.ADSCrossRefzbMATHGoogle Scholar
  12. 12.
    I.V. Naumov, I.V. Litvinov, R.F. Mikkelsen, and V.L. Okulov, Investigation of a wake decay behind a circular disc in a hydro channel at high Reynolds numbers, Thermophysics and Aeromechanics, 2015, Vol. 22, No. 6, P. 657–665.ADSCrossRefGoogle Scholar
  13. 13.
    Y.N. Nakamura, Vortex shedding from bluff bodies and a universal Strouhal number, J. Fluids Struct., 1996, Vol. 10, P. 159–171.ADSCrossRefGoogle Scholar
  14. 14.
    J.P. Bentley and A.R. Nichols, The mapping of vortex fields around single and dual bluff bodies, Flow Meas. Instrum., 1990, Vol. 1, P. 278–286.CrossRefGoogle Scholar
  15. 15.
    V.L. Okulov, I.V. Naumov, R.F. Mikkelsen, I.K. Kabardin, and J.N. Sørensen, A regular Strouhal number for large-scale instability in the far wake of a rotor, J. Fluid Mech., 2014, Vol. 747, P. 369–380.ADSCrossRefGoogle Scholar
  16. 16.
    I.V. Naumov, V.V. Rahmanov, V.L. Okulov, K.M. Velte, K.E. Mayer, and R.F. Mikkelsen, Flow diagnostics downstream of a tribladed rotor model, Thermophysics and Aeromechanics, 2012, Vol. 19, No. 2, P. 171–181.ADSCrossRefGoogle Scholar
  17. 17.
    I.V. Naumov, R.F. Mikkelsen, V.L. Okulov, and J.N. Sørensen, PIV and LDA measurements of the wake behind a wind turbine model, J. Phys.: Conference Series, 2014, Vol. 524, No. 1, P. 12168–12177.ADSGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2016

Authors and Affiliations

  • I. V. Naumov
    • 1
    Email author
  • I. V. Litvinov
    • 1
  • R. F. Mikkelsen
    • 2
  • V. L. Okulov
    • 1
    • 2
  1. 1.Kutateladze Institute of Thermophysics SB RASNovosibirskRussia
  2. 2.Technical University of DenmarkLyngbyDenmark

Personalised recommendations