- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review Fluids

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Modulation of flow over low-order topographies by low-order roughness

Shyuan Cheng1, Ali M. Hamed2, Matias Colombo3, and Leonardo P. Chamorro3,4,5,6,*

  • *Contact author: lpchamo@illinois.edu
PDF

Phys. Rev. Fluids 11, 064611 – Published 15 June, 2026

DOI: https://doi.org/10.1103/nrd5-ny95

Abstract

The interaction between low-order roughness and large-scale topography is experimentally investigated using high-resolution particle image velocimetry in a refractive-index-matched channel at two bulk Reynolds numbers differing by an order of magnitude, Re=4.0×103 and 4.0×104. A two-dimensional sinusoidal roughness is superimposed on a two-dimensional wavy wall to isolate the effects of multiscale surface modulation on near-wall turbulence. The added roughness reorganizes the flow by inducing larger coherent structures near the surface. Two-point correlations and integral length scales confirm enhanced near-wall coherence, while quadrant-hole analysis reveals a marked suppression of ejection events. This suppression weakens the local turbulence production term −〈u′v′〉dU/dy, leading to attenuation of the separated shear layer that develops downstream from the topographic crest within the adverse-pressure-gradient region. The resulting flow exhibits up to 25% lower peak turbulent kinetic energy and Reynolds shear stress relative to the smooth-wavy configuration. Even modest low-order roughness can therefore reorganize the coupling between near-wall and outer-layer motions, a mechanism that persists across an order of magnitude in Reynolds number and offers valuable insight for modeling transport and drag over natural and engineered surfaces.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (44)

  1. D. P. Zilker and T. J. Hanratty, Influence of the amplitude of a solid wavy wall on a turbulent flow. Part 2. Separated flows, J. Fluid Mech. 90, 257 (1979).
  2. J. Buckles, T. J. Hanratty, and R. J. Adrian, Turbulent flow over large-amplitude wavy surfaces, J. Fluid Mech. 140, 27 (1984).
  3. J. D. Kuzan, T. J. Hanratty, and R. J. Adrian, Turbulent flows with incipient separation over solid waves, Exp. Fluids 7, 88 (1989).
  4. H. S. Yoon, O. A. El-Samni, A. T. Huynh, H. H. Chun, H. J. Kim, A. H. Pham, and I. R. Park, Effect of wave amplitude on turbulent flow in a wavy channel by direct numerical simulation, Ocean Eng. 36, 697 (2009).
  5. S. Nakagawa and T. J. Hanratty, Particle image velocimetry measurements of flow over a wavy wall, Phys. Fluids 13, 3504 (2001).
  6. J. D. Hudson, L. Dykhno, and T. J. Hanratty, Turbulence production in flow over a wavy wall, Exp. Fluids 20, 257 (1996).
  7. K. Bhaganagar, J. Kim, and G. Coleman, Effect of roughness on wall-bounded turbulence, Flow, Turbul. Combust. 72, 463 (2004).
  8. S. Kuhn, C. Wagner, and P. R. von Rohr, Influence of wavy surfaces on coherent structures in a turbulent flow, Exp. Fluids 43, 251 (2007).
  9. A. Günther and P. R. Von Rohr, Large-scale structures in a developed flow over a wavy wall, J. Fluid Mech. 478, 257 (2003).
  10. N. Kruse, S. Kuhn, and P. R. von Rohr, Wavy wall effects on turbulence production and large-scale modes, J. Turbul. 7, N31 (2006).
  11. S. E. Belcher and J. C. R. Hunt, Turbulent flow over hills and waves, Annu. Rev. Fluid Mech. 30, 507 (1998).
  12. S. Leonardi, P. Orlandi, R. J. Smalley, L. Djenidi, and R. A. Antonia, Direct numerical simulations of turbulent channel flow with transverse square bars on one wall, J. Fluid Mech. 491, 229 (2003).
  13. S.-H. Lee and H. J. Sung, Direct numerical simulation of the turbulent boundary layer over a rod-roughened wall, J. Fluid Mech. 584, 125 (2007).
  14. T. Ikeda and P. A. Durbin, Direct simulations of a rough-wall channel flow, J. Fluid Mech. 571, 235 (2007).
  15. J. H. Lee, H. J. Sung, and P.-Å. Krogstad, Direct numerical simulation of the turbulent boundary layer over a cube-roughened wall, J. Fluid Mech. 669, 397 (2011).
  16. S. Ganju, S. C. C. Bailey, and C. Brehm, Amplitude and wavelength scaling of sinusoidal roughness effects in turbulent channel flow at fixed ℜτ=720, J. Fluid Mech. 937, A22 (2022).
  17. M. De Marchis and E. Napoli, Effects of irregular two-dimensional and three-dimensional surface roughness in turbulent channel flows, Int. J. Heat Fluid Flow 36, 7 (2012).
  18. R. J. Volino, M. P. Schultz, and K. A. Flack, Turbulence structure in a boundary layer with two-dimensional roughness, J. Fluid Mech. 635, 75 (2009).
  19. R. J. Hardy, J. L. Best, T. I. Marjoribanks, D. R. Parsons, and P. J. Ashworth, The influence of three-dimensional topography on turbulent flow structures over dunes in unidirectional flows, JGR Earth Surface 126, e2021JF006121 (2021).
  20. L. Djenidi, R. A. Antonia, M. Amielh, and F. Anselmet, A turbulent boundary layer over a two-dimensional rough wall, Exp. Fluids 44, 37 (2007).
  21. A. M. Hamed, A. Kamdar, L. Castillo, and L. P. Chamorro, Turbulent boundary layer over 2D and 3D large-scale wavy walls, Phys. Fluids 27, 106601 (2015).
  22. A. M. Hamed, M. Sadowski, Z. Zhang, and L. P. Chamorro, Transition to turbulence over 2D and 3D periodic large-scale roughnesses, J. Fluid Mech. 804, R6 (2016).
  23. G. Blois, K. T. Christensen, J. L. Best, G. Elliott, J. Austin, C. Dutton, M. Bragg, M. Garcia, and B. Fouke, A versatile refractive-index-matched flow facility for studies of complex flow systems across scientific disciplines, in 50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Nashville, Tennessee, 2012 (AIAA, Reston, VA, 2012), AIAA Paper No. 2012–0736.
  24. K. Bai and J. Katz, On the refractive index of sodium iodide solutions for index matching in PIV, Exp. Fluids 55, 1704 (2014).
  25. L. Chan, M. MacDonald, D. Chung, N. Hutchins, and A. Ooi, A systematic investigation of roughness height and wavelength in turbulent pipe flow in the transitionally rough regime, J. Fluid Mech. 771, 743 (2015).
  26. S. B. Pope, Turbulent flows, Meas. Sci. Technol. 12, 2020 (2001).
  27. L. P. Chamorro, C. Hill, S. Morton, C. Ellis, R. E. A. Arndt, and F. Sotiropoulos, On the interaction between a turbulent open channel flow and an axial-flow turbine, J. Fluid Mech. 716, 658 (2013).
  28. P. Saarenrinne and M. Piirto, Turbulent kinetic energy dissipation rate estimation from PIV velocity vector fields, Exp. Fluids 29, S300 (2000).
  29. L. Luznik, W. Zhu, R. Gurka, J. Katz, W. N. Smith, and T. R. Osborn, Distribution of energy spectra, Reynolds stresses, turbulence production, and dissipation in a tidally driven bottom boundary layer, J. Phys. Oceanogr. 37, 1527 (2007).
  30. J. Sheng, H. Meng, and R. O. Fox, A large eddy PIV method for turbulence dissipation rate estimation, Chem. Eng. Sci. 55, 4423 (2000).
  31. S. Cheng, S. Kaufman, V. Tipnis, J. L. Best, and L. P. Chamorro, Effects of low clay concentrations on nearly isotropic turbulence, Phys. Rev. Fluids 7, 073801 (2022).
  32. J. Hong, J. Katz, and M. P. Schultz, Near-wall turbulence statistics and flow structures over three-dimensional roughness in a turbulent channel flow, J. Fluid Mech. 667, 1 (2011).
  33. P. Cherukat, Y. Na, T. J. Hanratty, and J. B. McLaughlin, Direct numerical simulation of a fully developed turbulent flow over a wavy wall, Theor. Comput. Fluid Dyn. 11, 109 (1998).
  34. R. A. Antonia, J. Kim, and L. W. B. Browne, Some characteristics of small-scale turbulence in a turbulent duct flow, J. Fluid Mech. 233, 369 (1991).
  35. 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).
  36. K. P. Nolan, E. J. Walsh, and D. M. McEligot, Quadrant analysis of a transitional boundary layer subject to free-stream turbulence, J. Fluid Mech. 658, 310 (2010).
  37. W. Yue, C. Meneveau, M. B. Parlange, W. Zhu, R. Van Hout, and J. Katz, A comparative quadrant analysis of turbulence in a plant canopy, Water Resour. Res. 43, 2006WR005583 (2007).
  38. L. Keirsbulck, L. Labraga, A. Mazouz, and C. Tournier, Surface roughness effects on turbulent boundary layer structures, J. Fluids Eng. 124, 127 (2002).
  39. M. P. Schultz and K. A. Flack, Outer layer similarity in fully rough turbulent boundary layers, Exp. Fluids 38, 328 (2005).
  40. J. Finnigan, K. Ayotte, I. Harman, G. Katul, H. Oldroyd, E. Patton, D. Poggi, A. Ross, and P. Taylor, Boundary-layer flow over complex topography, Boundary-Layer Meteorol. 177, 247 (2020).
  41. J. M. Wallace, Quadrant analysis in turbulence research: History and evolution, Annu. Rev. Fluid Mech. 48, 131 (2016).
  42. R. J. Volino, M. P. Schultz, and K. A. Flack, Turbulence structure in boundary layers over periodic two-and three-dimensional roughness, J. Fluid Mech. 676, 172 (2011).
  43. S. Li, Z. Zhou, X. Yang, G. He, and H. Chen, Flow statistics and similarity in rough-wall periodic hill flows, Phys. Rev. Fluids 10, 104608 (2025).
  44. Y. Wu, H. Ren, and H. Tang, Turbulent flow over a rough backward-facing step, Int. J. Heat Fluid Flow 44, 155 (2013).

Outline

Information

Phys. Rev. Fluids 11, 064611– Published 15 June, 2026
  • Received 5 November 2025
  • Accepted 28 May 2026
Article part of CHORUS
Crossmark - Check for updates button

©2026 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation