Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-28T21:59:06.961Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of free-stream turbulence on rough surface turbulent boundary layers

Published online by Cambridge University Press:  10 September 2009

BRIAN BRZEK ,
SHEILLA TORRES-NIEVES ,
JOSÉ LEBRÓN ,
RAÚL CAL ,
CHARLES MENEVEAU  and
LUCIANO CASTILLO
BRIAN BRZEK
Affiliation:
Department of Mechanical Aeronautical and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
SHEILLA TORRES-NIEVES
Affiliation:
Department of Mechanical Aeronautical and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
JOSÉ LEBRÓN
Affiliation:
Department of Mechanical Aeronautical and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
RAÚL CAL
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21250, USA
CHARLES MENEVEAU
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21250, USA
LUCIANO CASTILLO*
Affiliation:
Department of Mechanical Aeronautical and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
*
†Email address for correspondence: castil2@rpi.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Several effects of nearly isotropic free-stream turbulence in transitionally rough turbulent boundary layers are studied using data obtained from laser Doppler anemometry measurements. The free-stream turbulence is generated with the use of an active grid, resulting in free-stream turbulence levels of up to 6.2%. The rough surface is characterized by a roughness parameter k+ ≈ 53, and measurements are performed at Reynolds numbers of up to Reθ = 11300. It is confirmed that the free-stream turbulence significantly alters the mean velocity deficit profiles in the outer region of the boundary layer. Consequently, the previously observed ability of the Zagarola & Smits (J. Fluid Mech., vol. 373, 1998, p. 33) velocity scale U∞δ*/δ to collapse results from both smooth and rough surface boundary layers, no longer applies in this boundary layer subjected to high free-stream turbulence. In inner variables, the wake region is significantly reduced with increasing free-stream turbulence, leading to decreased mean velocity gradient and production of Reynolds stress components. The effects of free-stream turbulence are clearly identifiable and significant augmentation of the streamwise Reynolds stress profiles throughout the entire boundary layer are observed, all the way down to the inner region. In contrast, the Reynolds wall-normal and shear stress profiles increase due to free-stream turbulence only in the outer part of the boundary layer due to the blocking effect of the wall. As a consequence, there is a significant portion of the boundary layer in which the addition of nearly isotropic turbulence in the free-stream, results in significant increases in anisotropy of the turbulence. To quantify which turbulence length scales contribute to this trend, second-order structure functions are examined at various distances from the wall. Results show that the anisotropy created by adding nearly isotropic turbulence in the free-stream resides mostly in the larger scales of the flow. Furthermore, by analysing the streamwise Reynolds stress equation, it can be predicted that it is the wall-normal gradient of 〈u2v〉 term that is responsible for the increase in 〈u2〉 profiles throughout the boundary layer (i.e. an efficient turbulent transport of turbulence away from the wall). Furthermore, a noticeable difference between the triple correlations for smooth and rough surfaces exists in the inner region, but no significant differences are seen due to free-stream turbulence. In addition, the boundary layer parameters δ*/δ95, H and cf are also evaluated from the experimental data. The flow parameters δ*/δ95 and H are found to increase due to roughness, but decrease due to free-stream turbulence, which has significance for flow control, particularly in delaying separation. Increases in cf due to high free-stream turbulence are also observed, associated with increased momentum flux towards the wall.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 635 , 25 September 2009 , pp. 207 - 243
Copyright
Copyright © Cambridge University Press 2009

References

REFERENCES

Akinlade, O. G., Bergstrom, D. J., Tachie, M. F. & Castillo, L. 2004 Outer flow scaling of smooth and rough wall turbulent boundary layers. Exp. Fluids 37, 604–612.CrossRefGoogle Scholar
Andreopoulos, J. & Bradshaw, P. 1981 Measurements of turbulence structure in the boundary layer on a rough surface. Bound. Layer Meteorol 20, 201–213.CrossRefGoogle Scholar
Antonia, R. A. & Krogstad, P. Å. 2001 Turbulence structure in boundary layers over different types of surface roughness. Fluid Dyn. Res. 28, 139–157.CrossRefGoogle Scholar
Aronson, D., Johansson, A. & Löfdahl, L. 1996 Shear-free turbulence near a wall. J. Fluid Mech. 338, 363–385.CrossRefGoogle Scholar
Bandyopadhyay, P. R. 1992 Reynolds number dependence of the free-stream turbulence effects on turbulent boundary layers. AIAA J. 30 (7), 1910–1912.CrossRefGoogle Scholar
Barrett, M. J. & Hollingsworth, D. K. 2003 a Correlating friction velocity in turbulent boundary layers subjected to free-stream turbulence. AIAA J. 41, 8, 1444–1451.CrossRefGoogle Scholar
Barrett, M. J. & Hollingsworth, D. K. 2003 b Heat transfer in turbulent boundary layers subjected to free-stream turbulence–Part 1: experimental results. J. Turbomach. 125, 232–241.CrossRefGoogle Scholar
Barrett, M. J. & Hollingsworth, D. K. 2003 c Heat transfer in turbulent boundary layers subjected to free-stream turbulence–Part 2: analysis and correlation. J. Turbomach. 125, 242–251.CrossRefGoogle Scholar
Blair, M. F. 1983 Influence of free-stream turbuence on turbulent boundary layer heat transfer and mean profile development–Part 2: analysis of results. J. Heat Transfer 105, 41–47.CrossRefGoogle Scholar
Bradshaw, P 2000 A note on ‘critical roughness height’ and ‘transitional roughness’. Phys. Fluids 12, 1611–1614.CrossRefGoogle Scholar
Brzek, B., Cal, R. B., Johansson, G. & Castillo, L. 2007 Inner and outer scalings in rough surface turbulent boundary layers. Phys. Fluids 19, 065101.CrossRefGoogle Scholar
Brzek, B., Cal, R. B., Johansson, G. & Castillo, L. 2008 Transitionally rough zero pressure gradient turbulent boundary layers. Exp. Fluids 44 (1), 115–124.CrossRefGoogle Scholar
Cal, R. B., Brzek, B., Johansson, T. G. & Castillo, L. 2008 Influence of external conditions on transitionally rough favorable pressure gradient turbulent boundary layers. J. Turbulence 9 (38), 1–22.CrossRefGoogle Scholar
Castillo, L. 1997 Similarity analysis of turbulent boundary layers. PhD thesis, State University of New York, Buffalo, NY.Google Scholar
Castillo, L. & Johansson, G. 2002 The effects of the upstream conditions on a low Reynolds number turbulent boundary layer with zero pressure gradient. J. Turbul. 3, 31, (1–19).CrossRefGoogle Scholar
Castro, I. 1984 Effects of free stream turbulence on low Reynolds number boundary layers. J. Fluid Mech. 585, 469–485.CrossRefGoogle Scholar
Castro, I. 2007 Rough wall boundary layers: mean flow universality. J. Fluids Engng 106, 298–306.CrossRefGoogle Scholar
Clauser, F. H. 1954 Turbulent boundary layers in adverse pressure gradients. J. Aero. Sci. 21, 91–108.CrossRefGoogle Scholar
Coles, D. E. 1962 Turbulent boundary layers in a compressible fluid. Tech. Rep. R-403-PR. RAND Corporation, Santa Monica, CA.Google Scholar
Comte-Bellot, G. & Corrsin, S. 1966 The use of a contraction to improve the isotropy of grid-generated turbulence. J. Fluid Mech. 25, 657–682.CrossRefGoogle Scholar
DeGraaff, D. B. & Eaton, J. K. 2000 Reynolds-number scaling of the flat-plate turbulent boundary layer. J. Fluid Mech. 422, 319–346.CrossRefGoogle Scholar
DeGraaff, D. B. & Eaton, J. K. 2001 A high-resolution laser Doppler anemometer: design, qualification, and uncertainty. Exp. Fluids 30, 522–530.CrossRefGoogle Scholar
George, W. K. 1990 Governing equations, experiments and the experimentalist. Exp. Therm. Fluid Sci. 3, 557–566.CrossRefGoogle Scholar
George, W. K. & Castillo, L. 1997 Zero-pressure gradient turbulent boundary layer. Appl. Mech. Rev. 50 (12), Part 1, 689–729.CrossRefGoogle Scholar
Hancock, P. E. & Bradshaw, P. 1983 The effect of free-stream turbulence on turbulent boundary layers. J. Fluids Engng 105, 284–289.CrossRefGoogle Scholar
Hancock, P. E. & Bradshaw, P. 1989 Turbulence structure of a boundary layer beneath a turbulent free-stream. J. Fluid Mech. 205, 45–76.CrossRefGoogle Scholar
Jiménez, J. 2004 Turbulent flows over rough walls. Annu. Rev. Fluid Mech. 36, 173–196.CrossRefGoogle Scholar
Johansson, G. & Castillo, L. 2002 Near-wall measurements in turbulent boundary layers using Laser Doppler Anemometry. In Proceedings of the FEDSM2002 – 31070, Montreal, Canada.Google Scholar
Kalter, M. & Fernholz, H. H. 2001 The reduction and elimination of a closed separation region by free-stream turbulence. J. Fluid Mech. 446, 271–308.CrossRefGoogle Scholar
Kang, H. S., Chester, S. & Meneveau, C. 2003 Decaying turbulence in an active-grid-generated flow and comparisons with large-eddy simulation. J. Fluid Mech. 480, 129–160.CrossRefGoogle Scholar
Krogstad, P.-Å. & Antonia, R. A. 1999 Surface roughness effects in turbulent boundary layers. Exp. Fluids 27, 450–460.CrossRefGoogle Scholar
Krogstad, P.-Å., Antonia, R. A. & Browne, L. W. B. 1992 Comparison between rough- and smooth-wall turbulent boundary layers. J. Fluid Mech. 245, 599–617.CrossRefGoogle Scholar
Leonardi, S., Orlandi, P., Smalley, R. J., Djenidi, L. & Antonia, R. A. 2003 Direct numerical simulations of turbulent channel flow with transverse square bars on one wall. J. Fluid Mech. 491, 229–238.CrossRefGoogle Scholar
Ligrani, P. M. & Moffat, R. J. 1986 Structure of transitionally rough and fully rough turbulent boundary layers. J. Fluid Mech. 162, 69–98.CrossRefGoogle Scholar
Mydlarski, L. & Warhaft, Z. 1996 On the onset of high Reynolds number grid generated wind tunnel turbulence. J. Fluid Mech. 320, 331–368.CrossRefGoogle Scholar
Monin, A. S. & Yaglom, A. M. 1971 Statistical Fluid Mechanics (ed. Lumley, John L.). MIT Press.Google Scholar
Österlund, J. 1999 Experimental studies of zero pressure-gradient turbulent boundary layer flow. PhD thesis, Royal Institute of Technology, Stockholm, Sweden.Google Scholar
Perry, A. E. & Li, J. D. 1990 Experimental support for the attached-eddy hypothesis in zero-pressure-gradient turbulent boundary layers. J. Fluid Mech. 218, 405–438.CrossRefGoogle Scholar
Radomsky, R. W. & Thole, K. A. 2002 Detail boundary layer measurements on a turbine stator vane at elevated free-stream turbulence levels. J. Turbomach. 124, 107–118.CrossRefGoogle Scholar
Roberts, S. K. & Yaras, M. I. 2005 Boundary layer transition affected by surface roughness and free-stream turbulence. J. Fluids Engng 127, 449–457.CrossRefGoogle Scholar
Schultz, M. P. & Flack, K. A. 2003 Turbulent boundary layers over surfaces smoothed by sanding. J. Fluids Engng 125, 863–870.CrossRefGoogle Scholar
Schultz, M. P. & Flack, K. A. 2005 Outer layer similarity in fully rough turbulent boundary layer. Exp. Fluids 38, 324–340.CrossRefGoogle Scholar
Schultz, M. P. & Flack, K. A. 2007 The rough wall turbulent boundary layer from the hydraulically smooth to the fully rough regime. J. Fluid Mech. 580, 381–405.CrossRefGoogle Scholar
Seo, J., Castillo, L., Johansson, G. & Hangan, H. 2004 Reynolds stress in turbulent boundary layers at high Reynolds number. J. Turbul. 5, 015.CrossRefGoogle Scholar
Stefes, B. & Fernholz, H. H. 2004 Skin friction and turbulence measurements in a boundary layer with zero-pressure gradient under the influence of high intensity free-stream turbulence. Euro. J. Mech. B/Fluids 23, 303–318.CrossRefGoogle Scholar
Tachie, M. F., Bergstrom, D. J. & Balachandar, 2000 Rough wall turbulent boundary layers in shallow open channel flow. J. Fluids Engng 122, 533–541.CrossRefGoogle Scholar
Tachie, M. F., Bergstrom, D. J. & Balachandar, 2003 Roughness effects in a low-Re θ open channel turbulent boundary layer. Exp. Fluids 35, 338–346.CrossRefGoogle Scholar
Thole, K. A. & Bogard, D. G. 1995 Enhanced heat transfer and shear stress due to high free-stream turbulence. J. Turbomach. 117, 418–424.CrossRefGoogle Scholar
Thole, K. A. & Bogard, D. G. 1996 High free-stream turbulence effects on turbulent boundary layers. J. Fluids Engng 118, 276–844.CrossRefGoogle Scholar
Townsend, A. A. 1976 The Structure of Turbulent Shear Flows. Cambridge University Press.Google Scholar
Zagarola, M. V. & Smits, A. J. 1998 Mean-flow scaling of turbulent pipe flow. J. Fluid Mech. 373, 33–79.CrossRefGoogle Scholar