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Outer-layer similarity in the presence of a practical rough-wall topography

Phys. Fluids 19, 085108 (2007); doi:10.1063/1.2741256

Published 24 August 2007

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Y. Wu and K. T. Christensen
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
High-resolution particle image velocimetry measurements are made in the streamwise–wall-normal plane of a zero-pressure-gradient turbulent boundary layer over smooth and rough walls at Retheta[approximate]13000. The roughness considered herein is replicated from a surface scan of a turbine blade damaged by deposition of foreign materials and its topography is highly irregular and contains a broad range of topographical scales. Two physical scalings of the same roughness topography are considered, yielding two different rough surfaces: RF1 with k=4.2  mm and RF2 with k=2.1  mm, where k is the average peak-to-valley roughness height. At Retheta[approximate]13000, these roughness conditions yield k+[equivalent]k/y*=207, delta/k=28, k<sub>s</sub><sup>+</sup>=115, and delta/ks=48 for RF1 and k+=91, delta/k=50, k<sub>s</sub><sup>+</sup>=29, and delta/ks=162 for RF2 (where delta is the boundary-layer thickness, ks is the equivalent sand-grain height, and y* is the viscous length scale). The mean velocity deficits along with the Reynolds normal and shear stress profiles for both roughness conditions collapse on the smooth-wall baseline in the outer layer when appropriately scaled by the friction velocity, utau. Probability density functions and quadrant analysis of the instantaneous events contributing to the mean Reynolds shear stress show similar outer-layer consistency between the smooth and rough cases when scaled appropriately with utau. In addition, one-dimensional, two-point streamwise, and wall-normal velocity autocorrelation coefficients are also found to collapse in the outer region, indicating a similarity in the spatial structure of the outer-layer turbulence. The observed collapse of the smooth- and rough-wall turbulence statistics in the outer layer supports Townsend's wall similarity hypothesis for flow over the unique surface topography considered herein. ©2007 American Institute of Physics
History: Received 24 February 2007; accepted 25 April 2007; published 24 August 2007
Permalink: http://link.aip.org/link/?PHFLE6/19/085108/1
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KEYWORDS and PACS

Keywords
PACS
  • 47.27.nb
    Boundary layer turbulence
  • 47.80.Jk
    Flow visualization and imaging
  • 47.85.-g
    Applied fluid mechanics
  • YEAR: 2007

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PUBLICATION DATA

ISSN:
1070-6631 (print)   1089-7666 (online)
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REFERENCES (45)
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  1. J. P. Bons, “St and Cf augmentation for real turbine roughness with elevated freestream turbulence,” J. Turbomach. 124, 632 (2002).
  2. R. I. Karlsson, “Studies of skin friction in turbulent boundary layers on smooth and rough walls,” Ph.D. thesis, Chalmers University of Technology, Göteborg, Sweden (1980).
  3. M. R. Raupach, R. A. Antonia, and S. Rajagopalan, “Rough-wall turbulent boundary layers,” Appl. Mech. Rev. 44, 1 (1991).
  4. J. Jimenez, “Turbulent flow over rough walls,” Annu. Rev. Fluid Mech. 36, 173 (2004).
  5. A. A. Townsend, The Structure of Turbulent Shear Flow, 2nd ed. (Cambridge University Press, Cambridge, UK, 1976).
  6. M. R. Raupach, “Conditional statistics of Reynolds stress in rough-wall and smooth-wall turbulent boundary layers,” J. Fluid Mech. 108, 363 (1981).
  7. K. A. Flack, M. P. Schultz, and T. A. Shapiro, “Experimental support for Townsend's Reynolds number similarity hypothesis on rough walls,” Phys. Fluids 17, 035102 (2005).
  8. A. E. Perry and J. D. Li, “Experimental support for the attached-eddy hypothesis in zero-pressure-gradient turbulent boundary layers,” J. Fluid Mech. 218, 405 (1990).
  9. P. M. Ligrani and R. J. Moffat, “Structure of transitionally rough and fully rough turbulent boundary layers,” J. Fluid Mech. 162, 69 (1986).
  10. P. R. Bandyopadhyay and R. D. Watson, “Structure of rough-wall turbulent boundary layers,” Phys. Fluids 31, 1877 (1988).
  11. J. Nikuradse, “Laws of flow in rough pipes,” NACA Technical Memorandum No. 1292 (1933).
  12. P. A. Krogstad, R. A. Antonia, and L. W. B. Browne, “Comparison between rough and smooth-wall turbulent boundary layers,” J. Fluid Mech. 245, 599 (1992).
  13. H. S. Shafi and R. A. Antonia, “Small-scale characteristics of a turbulent boundary layer over a rough wall,” J. Fluid Mech. 342, 263 (1997).
  14. P. A. Krogstad and R. A. Antonia, “Surface roughness effects in turbulent boundary layers,” Exp. Fluids 27, 450 (1999).
  15. L. Keirsbulck, L. Labraga, A. Mazouz, and C. Tournier, “Surface roughness effects on turbulent boundary layer structures,” J. Fluids Eng. 124, 127 (2002).
  16. J. P. Bons, R. P. Taylor, S. T. McClain, and R. B. Rivir, “The many faces of turbine surface roughness,” J. Turbomach. 123, 739 (2001).
  17. C. F. Colebrook, “Turbulent flow in pipes with particular reference to the transition region between the smooth- and rough-wall laws,” J. Inst. Civil Eng. 11, 133 (1939).
  18. M. Acharya, J. Bornstein, and M. P. Escudier, “Turbulent boundary layers on rough surfaces,” Exp. Fluids 4, 33 (1986).
  19. C. S. Subramanian, P. I. King, M. F. Reeder, S. Ou, and R. B. Rivir, “Effects of strong irregular roughness on the turbulent boundary layer,” Flow, Turbul. Combust. 72, 349 (2004).
  20. J. J. Allen, M. A. Shockling, G. J. Kunkel, and A. J. Smits, “Turbulent flow in smooth and rough pipes,” Philos. Trans. R. Soc. London, Ser. A 365, 699 (2007).
  21. C. D. Meinhart, “Investigation of turbulent boundary-layer structure using particle-image velocimetry,” Ph.D. thesis, University of Illinois at Urbana-Champaign (1994).
  22. R. A. Antonia and R. E. Luxton, “The response of a turbulent boundary layer to a step change in surface roughness. Part 1: Smooth to rough,” J. Fluid Mech. 48, 721 (1971).
  23. A. K. Prasad, R. J. Adrian, C. C. Landreth, and P. W. Offutt, “Effect of resolution on the speed and accuracy of particle image velocimetry interrogation,” Exp. Fluids 13, 105 (1992).
  24. K. T. Christensen, “The influence of peak-locking errors on turbulence statistics computed from PIV ensembles,” Exp. Fluids 36, 484 (2004).
  25. J. Westerweel, “Fundamentals of digital particle image velocimetry,” Meas. Sci. Technol. 8, 1379 (1997).
  26. K. T. Christensen and R. J. Adrian, “Measurement of instantaneous Eulerian acceleration fields by particle-image accelerometry: Method and accuracy,” Exp. Fluids 33, 759 (2002).
  27. M. P. Schultz and K. A. Flack, “Outer layer similarity in fully rough turbulent boundary layers,” Exp. Fluids 38, 328 (2005).
  28. S. Nakagawa and T. J. Hanratty, “Particle image velocimetry measurements of flow over a wavy wall,” Phys. Fluids 13, 3504 (2001).
  29. F. Bigillon, Y. Niño, and M. H. Garcia, “Measurements of turbulence characteristics in an open-channel flow over a transitionally-rough bed using particle-image velocimetry,” Exp. Fluids, 41, 857 (2006).
  30. H. Schlichting, Boundary-Layer Theory (McGraw-Hill, New York, 1979).
  31. J. S. Connelly, M. P. Schultz, and K. A. Flack, “Velocity-defect scaling for turbulent boundary layers with a range of relative roughness,” Exp. Fluids 40, 188 (2006).
  32. Y. Wu and K. T. Christensen, “Reynolds-stress enhancement associated with a short fetch of roughness in wall turbulence,” AIAA J. 44, 3098 (2006).
  33. S. S. Lu and W. W. Willmarth, “Measurements of the structure of the Reynolds stress in a turbulent boundary layer,” J. Fluid Mech. 60, 481 (1973).
  34. R. J. Adrian, C. D. Meinhart, and C. D. Tomkins, “Vortex organization in the outer region of the turbulent boundary layer,” J. Fluid Mech. 422, 1 (2000).
  35. J. Zhou, C. D. Meinhart, S. Balachandar, and R. Adrian, “Formation of coherent hairpin packets in wall turbulence,” in Self-Sustaining Mechanisms of Wall Turbulence, edited by R. L. Panton (Computational Mechanics, Southampton, UK, 1997), pp. 109–134.
  36. K. T. Christensen, Y. Wu, R. J. Adrian, and W. Lai, “Statistical imprints of structure in wall turbulence,” AIAA Pap. 2004-1116 (2004).
  37. P. A. Krogstad and R. A. Antonia, “Structure of turbulent boundary layers on smooth and rough walls,” J. Fluid Mech. 277, 1 (1994).
  38. J. Zhou, R. J. Adrian, and S. Balachandar, “Autogeneration of near-wall vortical structures in channel flow,” Phys. Fluids 8, 288 (1996).
  39. M. P. Schultz and K. A. Flack, “Turbulent boundary layers over surfaces smoothed by sanding,” J. Fluids Eng. 125, 863 (2003).
  40. A. J. Grass, “Structural features of turbulent flow over smooth and rough boundaries,” J. Fluid Mech. 50, 233 (1971).
  41. P. A. Krogstad, H. I. Andersson, O. M. Bakken, and A. Ashrafian, “An experimental and numerical study of channel flow with rough walls,” J. Fluid Mech. 530, 327 (2005).
  42. O. M. Bakken, P. A. Krogstad, A. Ashrafian, and H. I. Andersson, “Reynolds number effects in the outer layer of the turbulent flow in a channel with rough walls,” Phys. Fluids 17, 065101 (2005).
  43. M. F. Tachie, D. J. Bergstrom, and R. Balachandar, “Roughness effects in low-Retheta open-channel turbulent boundary layers,” Exp. Fluids 35, 338 (2003).
  44. M. F. Tachie, D. J. Bergstrom, and R. Balachandar, “Rough wall turbulent boundary layers in shallow open channel flow,” J. Fluids Eng. 122, 533 (2000).
  45. K. Bhaganagar, J. Kim, and G. Coleman, “Effect of roughness on wall-bounded turbulence,” Flow, Turbul. Combust. 72, 463 (2004).

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