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Near-wall velocity field in turbulent Rayleigh-Bénard convection with rough surface

Ronald du Puits*

  • *Contact author: ronald.dupuits@tu-ilmenau.de
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Phys. Rev. Fluids 10, 113501 – Published 5 November, 2025

DOI: https://doi.org/10.1103/sl4p-fytk

Abstract

We present measurements of the near-wall velocity field in turbulent Rayleigh-Bénard convection with a partially rough horizontal surface. These measurements cover Rayleigh numbers ranging from Ra=5.8×1010 to Ra=8.0×1011, while the Prandtl number was fixed at Pr=0.7. The measurements have been undertaken in the large-scale convection experiment “Barrel of Ilmenau,” which provides a very high resolution in space and time. The measurements confirm the prominent role of the ratio between the thickness of the boundary layer δth and the height of the roughness elements h, although transition effects only appear below δth/h≈0.6 in our experiments. In addition, we calculated the ratio between the turbulent kinetic energy and the average kinetic energy in the boundary layer. This ratio remains virtually constant up to Ra=4.2×1011 and increases beyond this value. This is another indication of a qualitative transition of the boundary layer flow field. We observed this transition above both the TOP and above the VALLEY regions of the rough surface, concluding that both regions may contribute similarly to an increase in heat flux. The transition in the flow field is purely induced by viscous effects. The Richardson number, based on the thickness of the boundary layer and the velocity of the mean wind, is much smaller than one for all Rayleigh numbers investigated. This indicates that viscous effects dominate the near-wall flow field, and buoyancy does not play any role in the variation of the flow field here. We have also analysed time series of the wall-normal velocity component w in the plane where the temperature fluctuates at its maximum. The distribution of the fluctuations of w deviates from a normal distribution for all investigated Rayleigh numbers. In particular, the distributions exhibit broader tails on both sides. However, the distributions show just a little asymmetry, which we would expect as a signature of thermal plumes.

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References (32)

  1. R. du Puits, Thermal boundary layers in turbulent Rayleigh-Bénard convection with rough and smooth plates: A one-to-one comparison, Phys. Rev. Fluids 9, 023501 (2024).
  2. E. D. Siggia, High Rayleigh number convection, Annu. Rev. Fluid Met. 26, 137 (1994).
  3. G. Ahlers, S. Grossmann, and D. Lohse, Heat transfer and large scale dynamics in turbulent Rayleigh-Bénard convection, Rev. Mod. Phys. 81, 503 (2009).
  4. F. Chilla and J. Schumacher, New perspectives in turbulent Rayleigh-Bénard convection, Eur. Phys. J. E 35, 58 (2012).
  5. Y. Shen, P. Tong, and K.-Q. Xia, Turbulent convection over rough surfaces, Phys. Rev. Lett. 76, 908 (1996).
  6. E. Villermaux, Transfer at rough sheared interfaces, Phys. Rev. Lett. 81, 4859 (1998).
  7. S. Ciliberto and C. Laroche, Random roughness of boundary increases the turbulent convection scaling exponent, Phys. Rev. Lett. 82, 3998 (1999).
  8. P.-E. Roche, B. Castaing, B. Chabaud, and B. Hébral, Observation of the 1/2 power law in Rayleigh-Bénard convection, Phys. Rev. E 63, 045303(R) (2001).
  9. O. Shishkina and C. Wagner, Modelling the influence of wall roughness on heat transfer in thermal convection, J. Fluid Mech. 686, 568 (2011).
  10. D. Goluskin and C. R. Doering, Bounds for convection between rough boundaries, J. Fluid Mech. 804, 370 (2016).
  11. S. Toppaladoddi, S. Succi, and J. S. Wettlaufer, Roughness as a route to the ultimate regime of thermal convection, Phys. Rev. Lett. 118, 074503 (2017).
  12. X. Zhu, R. J. A. M. Stevens, R. Verzicco, and D. Lohse, Roughness-Facilitated local 1/2 Scaling does not imply the onset of the ultimate regime of thermal convection, Phys. Rev. Lett. 119, 154501 (2017).
  13. X.-L. Qiu, K.-Q. Xia, and P. Tong, Experimental study of velocity boundary layer near a rough conducting surface in turbulent natural convection, J. Turbul. 6, N30 (2005).
  14. O. Liot, J. Salort, R. Kaiser, R. du Puits, and F. Chillà, Boundary layer structure in a rough Rayleigh-Bénard cell filled with air, J. Fluid Mech. 786, 275 (2016).
  15. O. Liot, Q. Ehlinger, E. Rusaouën, T. Coudarchet, J. Salort, and F. Chillà, Velocity fluctuations and boundary layer structure in a rough Rayleigh-Bénard cell filled with water, Phys. Rev. Fluids 2, 044605 (2017).
  16. Y.-C. Xie and K.-Q. Xia, Turbulent thermal convection over rough plates with varying roughness geometries, J. Fluid Mech. 825, 573 (2017).
  17. M. J. Tummers and M. Steunebrink, Effect of surface roughness on heat transfer in Rayleigh-Bénard convection, Int. J. Heat Mass Transf. 139, 1056 (2019).
  18. M. Belkadi, A. Sergent, Y. Fraigneau, and B. Podvin, On the role of roughness valleys in turbulent Rayleigh–Bénard convection, J. Fluid Mech. 923, A6 (2021).
  19. M. Sharma, K. Chand, and A. K. De, Dominant heat transfer mechanism with conical roughness in a cubical box in turbulent Rayleigh–Bénard convection, Phys. Fluids 36, 065124 (2024).
  20. R. du Puits, C. Resagk, and A. Thess, Thermal boundary layers in turbulent Rayleigh–Bénard convection at aspect ratios between 1 and 9, New J. Phys. 15, 013040 (2013).
  21. C. Sun, K.-Q. Xia, and P. Tong, Three-dimensional flow structures and dynamics of turbulent thermal convection in a cylindrical cell, Phys. Rev. E 72, 026302 (2005).
  22. R. du Puits and C. Willert, The evolution of the boundary layer in turbulent Rayleigh-Bénard convection in air, Phys. Fluids 28, 044108 (2016).
  23. B. Wieneke, Stereo-PIV using self-calibration on particle images, Exp. Fluids 39, 267 (2005).
  24. J.-C. Tisserand, M. Creyssels, Y. Gasteuil, H. Pabiou, M. Gibert, B. Castaing, and F. Chilla, Comparison between rough and smooth plates within the same Rayleigh-Bénard cell, Phys. Fluids 23, 015105 (2011).
  25. J. Salort, O. Liot, E. Rusaouen, F. Seychelles, J.-C. Tisserand, M. Creyssels, B. Castaing, and F. Chillà, Thermal boundary layer near roughnesses in turbulent Rayleigh-Bénard convection: Flow structure and multistability, Phys. Fluids 26, 015112 (2014).
  26. R. du Puits, A. Loesch, J. Salort, and F. Chillà, Thermal boundary layers in turbulent Rayleigh-Bénard convection with rough surfaces, arXiv:1710.06206.
  27. B. Castaing, G. Gunaratne, F. Heslot, L. Kadanoff, A. Libchaber, S. Thomae, X.-Z. Wu, S. Zaleski, and G. P. Zanetti, Scaling of hard thermal turbulence in Rayleigh-Bénard convection, J. Fluid Mech. 204, 1 (1989).
  28. S. Grossmann and D. Lohse, Fluctuations in turbulent Rayleigh–Bénard convection: The role of plumes, Phys. Fluids 16, 4462 (2004).
  29. D. Funfschilling and G. Ahlers, Plume motion and large-scale circulation in a cylindrical Rayleigh-Bénard cell, Phys. Rev. Lett. 92, 194502 (2004).
  30. E. Brown and G. Ahlers, The origin of oscillations of the large-scale circulation of turbulent Rayleigh–Bénard convection, J. Fluid Mech. 638, 383 (2009).
  31. H.-D. Xi, S.-Q. Zhou, Q. Zhou, T.-S. Chan, and K.-Q. Xia, Origin of the temperature oscillation in turbulent thermal convection, Phys. Rev. Lett. 102, 044503 (2009).
  32. R. du Puits, Case 5: The near wall velocity field in turbulent Rayleigh-Bénard convection with rough surface, in: https://www.tu-ilmenau.de/universitaet/fakultaeten/fakultaet-maschinenbau/profil/institute-und-fachgebiete/fachgebiet-aerodynamik/ilmenauer-fass/datenbank-1/case-5.

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Phys. Rev. Fluids 10, 113501– Published 5 November, 2025
  • Received 13 May 2025
  • Accepted 8 October 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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