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A New Way to Determine the Wall Position and Friction Velocity in Wall-Bounded Turbulent Flows

  • P. H. AlfredssonEmail author
  • R. Örlü
Part of the Springer Proceedings in Physics book series (SPPHY, volume 141)

Abstract

Studies of turbulent boundary layers are often focussed on the near wall region. In experiments an accurate determination of the wall (say within 10 μm) with respect to the measurement probe is not easily achieved through optical or mechanical measurements (see e.g. Ref. [1]). Also the friction velocity (u τ ) is hard to determine with high accuracy. One possibility is to utilize the linear velocity profile (U  +  = y  + ) to determine one or both of the mentioned quantities, but is usually impeded by the fact that the hot-wire readings are affected by heat transfer to the wall. The motivation here is to utilize the cumulative distribution function (CDF) of the streamwise velocity in a way so that the influence of the heat transfer can be avoided and thereby obtain accurate estimates of both the wall position and friction velocity.

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References

  1. 1.
    Örlü, R., Fransson, J.H.M., Alfredsson, P.H.: On near wall measurements of wall bounded flows – the necessity of an accurate determination of the wall position. Prog. Aero. Sci. 46, 353–387 (2010)CrossRefGoogle Scholar
  2. 2.
    Örlü, R.:: Experimental studies in jet flows and zero pressure-gradient turbulent boundary layers. PhD thesis, KTH Mechanics, Stockholm, Sweden (2009)Google Scholar
  3. 3.
    Alfredsson, P.H., Örlü: The diagnostic plot – a litmus test for wall bounded turbulence data. Eur. J. Fluid Mech. B/Fluids 29, 403–406 (2010)zbMATHCrossRefGoogle Scholar
  4. 4.
    Schlatter, P., Örlü, R.: Assessment of direct numerical simulation data of turbulent boundary layers. J. Fluid Mech. 659, 116–126 (2010)zbMATHCrossRefGoogle Scholar
  5. 5.
    Alfredsson, P.H., Örlü, R., Schlatter, P.: The viscous sublayer revisited—exploiting self-similarity to determine the wall position and friction velocity. Exp. Fluids 51, 271–280 (2011)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Linné FLOW Centre, KTH MechanicsRoyal Institute of TechnologyStockholmSweden

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