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New perspectives on the impulsive roughness-perturbation of a turbulent boundary layer

  • I. JACOBI (a1) and B. J. McKEON (a1)

Abstract

The zero-pressure-gradient turbulent boundary layer over a flat plate was perturbed by a short strip of two-dimensional roughness elements, and the downstream response of the flow field was interrogated by hot-wire anemometry and particle image velocimetry. Two internal layers, marking the two transitions between rough and smooth boundary conditions, are shown to represent the edges of a ‘stress bore’ in the flow field. New scalings, based on the mean velocity gradient and the third moment of the streamwise fluctuating velocity component, are used to identify this ‘stress bore’ as the region of influence of the roughness impulse. Spectral composite maps reveal the redistribution of spectral energy by the impulsive perturbation – in particular, the region of the near-wall peak was reached by use of a single hot wire in order to identify the significant changes to the near-wall cycle. In addition, analysis of the distribution of vortex cores shows a distinct structural change in the flow associated with the perturbation. A short spatially impulsive patch of roughness is shown to provide a vehicle for modifying a large portion of the downstream flow field in a controlled and persistent way.

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Corresponding author

Email address for correspondence: jacobi@caltech.edu

References

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Andreopoulos, J. & Wood, D. H. 1982 The response of a turbulent boundary layer to a short length of surface roughness. J. Fluid Mech. 118, 143164.
Antonia, R. A. & Luxton, R. E. 1971 a The response of a turbulent boundary layer to a step change in surface roughness. Part 1. Smooth to rough. J. Fluid Mech. 48 (4), 721761.
Antonia, R. A. & Luxton, R. E. 1971 b The response of a turbulent boundary layer to an upstanding step change in surface roughness. Trans. ASME: J. Basic Engng 93, 2234.
Antonia, R. A. & Luxton, R. E. 1972 The response of a turbulent boundary layer to a step change in surface roughness. Part 2. Rough-to-smooth. J. Fluid Mech. 53 (4), 737757.
DeGraaff, D. B. & Eaton, J. K. 2000 Reynolds-number scaling of the flat-plate turbulent boundary layer. J. Fluid Mech. 422, 319346.
Erm, L. P. & Joubert, P. N. 1991 Low-Reynolds-number turbulent boundary layers. J. Fluid Mech. 230, 144.
Freymuth, P. 1977 Frequency response and electronic testing for constant-temperature hot-wire anemometers. J. Phys. E: Sci, Instrum. 10, 705.
Hamilton, J. M., Kim, J. & Waleffe, F. 1995 Regeneration mechanisms of near-wall turbulence structures. J. Fluid Mech. 287, 317348.
Hutchins, N. & Marusic, I. 2007 Large-scale influences in near-wall turbulence. Phil. Trans. R. Soc. Lond. 365, 647664.
Hutchins, N., Nickels, T. B., Marusic, I. & Chong, M. S. 2009 Hot-wire spatial resolution issues in wall-bounded turbulence. J. Fluid Mech. 635, 103136.
Jiménez, J. 2004 Turbulent flows over rough walls. Annu Rev. Fluid Mech. 36, 173196.
Jiménez, J. & Pinelli, A. 1999 The autonomous cycle of near-wall turbulence. J. Fluid Mech. 389, 335359.
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, 229238.
Monty, J. P., Hutchins, N., Ng, H. C. H., Marusic, I. & Chong, M. S. 2009 A comparison of turbulent pipe, channel and boundary layer flows. J. Fluid Mech. 632, 431442.
Morrison, J. F. 2010 Boundary layers under strong distortion: an experimentalist's view. In Prediction of Turbulent Flows, pp. 163206. Cambridge University Press.
Morrison, J. F., McKeon, B. J., Jiang, W. & Smits, A. J. 2004 Scaling of the streamwise velocity component in turbulent pipe flow. J. Fluid Mech. 508, 99131.
Pearson, B. R., Elavarasan, R. & Antonia, R. A. 1997 Effect of a short roughness strip on a turbulent boundary layer. Appl. Sci. Res. 59, 6175.
Smits, A. J. & Wood, D. H. 1985 The response of turbulent boundary layers to sudden perturbations. Annu. Rev. Fluid Mech. 17, 321358.
Smits, A. J., Young, S. T. B. & Bradshaw, P. 1979 The effect of short regions of high curvature on turbulent boundary layers. J. Fluid Mech. 94, 209242.
Westerweel, J. 1997 Fundamentals of digital particle image velocimetry. Meas. Sci. Technol. 8, 13791392.
Wu, Y. & Christensen, K. T. 2006 Population trends of spanwise vortices in wall turbulence. J. Fluid Mech. 568, 5576.
Zhou, J., Adrian, R. J., Balachandar, S. & Kendall, T. M. 1999 Mechanisms for generating coherent packets of hairpin vortices in channel flow. J. Fluid Mech. 387, 353396.
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New perspectives on the impulsive roughness-perturbation of a turbulent boundary layer

  • I. JACOBI (a1) and B. J. McKEON (a1)

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