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Particle image velocimetry measurements of a transitional boundary layer under free stream turbulence

Published online by Cambridge University Press:  23 May 2012

K. P. Nolan
Affiliation:
Department of Mechanical and Aeronautical Engineering, Stokes Institute, University of Limerick, Limerick, Ireland
E. J. Walsh
Affiliation:
Department of Mechanical and Aeronautical Engineering, Stokes Institute, University of Limerick, Limerick, Ireland

Abstract

High-speed particle image velocimetry (PIV) measurements of bypass transition reveal the breakdown of the ubiquitous streaks into turbulent spots. Individual streak velocity profiles are examined and contrasted with the root mean square profiles typically reported. An estimation of streak amplitude based on the modulation of the instantaneous boundary layer thickness is proposed. Examination of the PIV velocity fields shows how turbulent spot precursors, identified with concurrent hot-film recordings, consist of streamwise arrangements of positive and negative streaks. As secondary instability progresses, the interface between these streaks is observed to result in turbulent structures. In an attempt to further elucidate the role of the free stream turbulence, correlation maps are generated to determine the extent of the wall-normal fluctuations. Significant damping of the free stream is found within the boundary layer for all Reynolds numbers prior to the onset of spot precursors.

Type
Papers
Copyright
Copyright © Cambridge University Press 2012

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References

1. Andersson, P., Berggren, M. & Henningson, D. S. 1999 Optimal disturbances and bypass transition in boundary layers. Phys. Fluids 11 (1), 134150.CrossRefGoogle Scholar
2. Andersson, P., Brandt, L., Bottaro, A. & Henningson, D. S. 2001 On the breakdown of boundary layer streaks. J. Fluid Mech. 428, 2960.CrossRefGoogle Scholar
3. Anthony, R. J., Jones, T. V. & LaGraff, J. E. 2005 High frequency surface heat flux imaging of bypass transition. Trans. ASME: J. Turbomach. 127, 241.Google Scholar
4. Banerjee, A., Mandal, A. & Dey, J. 2006 Particle image velocimetry studies of an incipient spot in the Blasius boundary layer. Exp. Fluids 40 (6), 928941.CrossRefGoogle Scholar
5. Bradshaw, P. 1965 The effect of wind-tunnel screens on nominally two-dimensional boundary layers. J. Fluid Mech. 22 (04), 679687.CrossRefGoogle Scholar
6. Brandt, L. & Henningson, D. S. 2002 Transition of streamwise streaks in zero-pressure-gradient boundary layers. J. Fluid Mech. 472, 229261.CrossRefGoogle Scholar
7. Brandt, L. & de Lange, H. C. 2008 Streak interactions and breakdown in boundary layer flows. Phys. Fluids 20 (2), 024107.CrossRefGoogle Scholar
8. Brandt, L., Schlatter, P. & Henningson, D. S. 2004 Transition in boundary layers subject to free-stream turbulence. J. Fluid Mech. 517, 167198.CrossRefGoogle Scholar
9. Chong, T. P. & Zhong, S. 2005 On the three-dimensional structure of turbulent spots. Trans. ASME: J. Turbomach. 127 (3), 545551.Google Scholar
10. Cossu, C., Brandt, L., Bagheri, S. & Henningson, D. S. 2011 Secondary threshold amplitudes for sinuous streak breakdown. Phys. Fluids 23 (7), 074103.CrossRefGoogle Scholar
11. Crow, S. C. 1966 The spanwise perturbation of two-dimensional boundary layers. J. Fluid Mech. 24 (01), 153164.CrossRefGoogle Scholar
12. Goldstein, M. E. & Wundrow, D. W. 1998 On the environmental realizability of algebraically growing disturbances and their relation to Klebanoff modes. Theor. Comput. Fluid Dyn. 10, 171.CrossRefGoogle Scholar
13. Hedley, T. B. & Keffer, J. F. 1974 Some turbulent/non-turbulent properties of the outer intermittent region of a boundary layer. J. Fluid Mech. 64 (04), 645678.CrossRefGoogle Scholar
14. Hernon, D. & Walsh, E. J. 2007 Enhanced energy dissipation rates in laminar boundary layers subjected to elevated levels of free stream turbulence. Fluid Dyn. Res. 39 (4), 305319.CrossRefGoogle Scholar
15. Hernon, D., Walsh, E. J. & McEligot, D. M. 2007a Experimental investigation into the routes to bypass transition and the shear-sheltering phenomenon. J. Fluid Mech. 591, 461479.CrossRefGoogle Scholar
16. Hernon, D., Walsh, E. J. & McEligot, D. M. 2007b Instantaneous fluctuation velocity and skewness distributions upstream of transition onset. Intl J. Heat Fluid Flow 28 (6), 12721279.CrossRefGoogle Scholar
17. Jacobs, R. G. & Durbin, P. A. 1998 Shear sheltering and the continuous spectrum of the Orr–Sommerfeld equation. Phys. Fluids 10 (8), 20062011.CrossRefGoogle Scholar
18. Jacobs, R. G. & Durbin, P. A. 2001 Simulations of bypass transition. J. Fluid Mech. 428, 185212.CrossRefGoogle Scholar
19. Jonáš, P., Mazur, O. & Uruba, V. 2000 On the receptivity of the bypass transition to the length scale of the outer stream turbulence. Eur. J. Mech. (B/Fluids) 19 (5), 707722.CrossRefGoogle Scholar
20. Klebanoff, P. S. 1971 Effect of free-stream turbulence on the laminar boundary layer. Bull. Am. Phys. Soc. 10, 1323.Google Scholar
21. Luchini, P. 2000 Reynolds-number-independent instability of the boundary layer over a flat surface: optimal perturbations. J. Fluid Mech. 404, 289309.CrossRefGoogle Scholar
22. Lundell, F. & Alfredsson, P. H. 2004 Streamwise scaling of streaks in laminar boundary layers subjected to free-stream turbulence. Phys. Fluids 16 (5), 18141817.CrossRefGoogle Scholar
23. Mandal, A. C., Venkatakrishnan, L. & Dey, J. 2010 A study on boundary-layer transition induced by free-stream turbulence. J. Fluid Mech. 660, 114146.CrossRefGoogle Scholar
24. Mans, J., Kadijk, E., de Lange, H. & Steenhoven, A. 2005 Breakdown in a boundary layer exposed to free-stream turbulence. Exp. Fluids 39 (6), 10711083.CrossRefGoogle Scholar
25. Mans, J., de Lange, H. C. & van Steenhoven, A. A. 2007 Sinuous breakdown in a flat plate boundary layer exposed to free-stream turbulence. Phys. Fluids 19 (8), 088101.CrossRefGoogle Scholar
26. Matsubara, M. & Alfredsson, P. H. 2001 Disturbance growth in boundary layers subjected to free-stream turbulence. J. Fluid Mech. 430, 149.CrossRefGoogle Scholar
27. Nagarajan, S., Lele, S. K. & Ferziger, J. H. 2007 Leading-edge effects in bypass transition. J. Fluid Mech. 572, 471504.CrossRefGoogle Scholar
28. Nolan, K. P., Walsh, E. J. & McEligot, D. M. 2010 Quadrant analysis of a transitional boundary layer subject to free-stream turbulence. J. Fluid Mech. 658, 310335.CrossRefGoogle Scholar
29. Nolan, K. P., Walsh, E. J., McEligot, D. M. & Volino, R. J. 2007 Predicting entropy generation rates in transitional boundary layers based on intermittency. Trans. ASME: J. Turbomach. 129 (3), 512517.Google Scholar
30. Roach, P. E. 1987 The generation of nearly isotropic turbulence by means of grids. Intl J. Heat Fluid Flow 8 (2), 8292.CrossRefGoogle Scholar
31. Sabatino, D. & Smith, C. 2002 Simultaneous velocity–surface heat transfer behavior of turbulent spots. Exp. Fluids 33 (1), 1321.CrossRefGoogle Scholar
32. Schoppa, W. & Hussain, F. 2002 Coherent structure generation in near-wall turbulence. J. Fluid Mech. 453, 57108.CrossRefGoogle Scholar
33. Schrader, L.-U., Brandt, L., Mavriplis, C. & Henningson, D. S. 2010 Receptivity to free-stream vorticity of flow past a flat plate with elliptic leading edge. J. Fluid Mech. 653, 245271.CrossRefGoogle Scholar
34. Schröder, A. & Kompenhans, J. 2004 Investigation of a turbulent spot using multi-plane stereo particle image velocimetry. Exp. Fluids 36 (1), 8290.CrossRefGoogle Scholar
35. Stewartson, K. 1957 On asymptotic expansion in the theory of boundary layer. J. Math. Phys. 36, 137.CrossRefGoogle Scholar
36. Vaughan, N. J. & Zaki, T. A. 2011 Stability of zero-pressure-gradient boundary layer distorted by unsteady Klebanoff streaks. J. Fluid Mech. 681, 116153.CrossRefGoogle Scholar
37. Walsh, E. J., Hernon, D., Davies, M. R. D. & McEligot, D. M. 2005 Preliminary measurements from a new plate facility for aerodynamic research. In Proceedings of the 6th European Turbomachinery Conference: Fluid Dynamics and Thermodynamics, Lille.Google Scholar
38. Wundrow, D. W. & Goldstein, M. E. 2001 Effect on a laminar boundary layer of small amplitude streamwise vorticity in the upstream flow. J. Fluid Mech. 426, 229262.CrossRefGoogle Scholar
39. Wygnanski, I., Sokolov, M. & Friedman, D. 1976 On a turbulent ‘spot’ in a laminar boundary layer. J. Fluid Mech. 78 (04), 785819.CrossRefGoogle Scholar
40. Yaras, M. I. 2007 An experimental study of artificially-generated turbulent spots under strong favorable pressure gradients and free-stream turbulence. Trans. ASME: J. Fluids Engng 129 (5), 563572.Google Scholar
41. Zaki, T. & Durbin, P. A. 2005 Mode interaction and the bypass route to transition. J. Fluid Mech. 531, 85.CrossRefGoogle Scholar