Hostname: page-component-84b7d79bbc-g78kv Total loading time: 0 Render date: 2024-07-30T12:33:08.023Z Has data issue: false hasContentIssue false
  • English
  • Français

Vortex dynamics of a low aspect ratio cantilevered cylinder immersed in a boundary layer

Published online by Cambridge University Press:  25 August 2020

Samantha Gildersleeve  and
Michael Amitay Open the ORCID record for Michael Amitay [Opens in a new window]
Samantha Gildersleeve
Affiliation:
Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY12180, USA
Michael Amitay*
Affiliation:
Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY12180, USA
*
†Email address for correspondence: amitam@rpi.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

The flow physics associated with the interaction of a low aspect ratio, cantilevered cylindrical pin with a flow over a flat plate was investigated experimentally using oil visualizations and stereoscopic particle image velocimetry. The interactions of the vortical structures were explored for laminar, transitional and turbulent incoming boundary layers, where the flow's sensitivity to the pin's aspect ratio and its relative submergence within the boundary layer was studied. The surrounding flow is highly sensitive to subtle changes in these parameters (both are order 1) due to strong dependence between the flow over the pin's free end and its wake. These flow structures are heavily influenced by competing mechanisms of self-induction and shear flow due to outer fluid entrainment and the proximity to the wall. In particular, the observed vortical features exhibit strong inter-dependencies in the near wake. For a turbulent boundary layer, the resultant ‘arch-like’ structure is observed to be slightly stretched in the axial direction. Whereas, under laminar inflow conditions, the reduced shear and turbulence intensity facilitate a wider wake and a stronger downwash from the leeward edge, resulting in a concave ‘M-shaped’ vortex, affecting the formation and evolution of the trailing vortex pair. In addition, larger aspect ratios result in an increased magnitude of downwash into the wake, which re-energizes the near-wall flow. Whereas, for lower aspect ratios, the level of interaction between vortical features decreases due to a reduced downwash and weaker shear. These flow characteristics are discussed in detail in the paper.

JFM classification

Vortex Flows: Vortex dynamics Vortex Flows: Vortex interactions Wakes/Jets: Wakes
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 901 , 25 October 2020 , A18
Check for updates
Copyright
© The Author(s), 2020. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

‡

Present address: NASA Langley Research Center, Hampton, VA 23681-2199, USA.

References

REFERENCES

Afgan, I., Moulinec, C., Prosser, R. & Laurence, D. 2007 Large eddy simulation of turbulent flow for wall mounted cantilever cylinders of aspect ratio 6 and 10. Intl J. Heat Fluid Flow 28 (4), 561–574.CrossRefGoogle Scholar
Baker, C. J. 1979 The laminar horseshoe vortex. J. Fluid Mech. 95 (2), 347–367.CrossRefGoogle Scholar
Baker, C. J. 1980 The turbulent horseshoe vortex. J. Wind Engng Ind. Aerodyn. 6 (1–2), 9–23.CrossRefGoogle Scholar
Baker, C. J. 1991 The oscillation of horseshoe vortex systems. Trans. ASME: J. Fluids Engng 113, 489–495.Google Scholar
Bourgeois, J. A., Sattari, P. & Martinuzzi, R. J. 2011 Alternating half-loop shedding in the turbulent wake of a finite surface-mounted square cylinder with a thin boundary layer. Phys. Fluids 23 (9), 095101.CrossRefGoogle Scholar
Christensen, K. T. & Scarano, F. 2015 Uncertainty quantification in particle image velocimetry. Meas. Sci. Technol. 26 (7), 070201.CrossRefGoogle Scholar
DeMauro, E. P., Dell'Orso, H., Zaremski, S., Leong, C. M. & Amitay, M. 2015 Control of laminar separation bubble on NACA 0009 airfoil using electroactive polymers. AIAA J. 53 (8), 2270–2279.CrossRefGoogle Scholar
Etzold, F. & Fiedler, H. 1976 The near-wake structure of a cantilevered cylinder in a cross-flow. Z. Flugwiss. 24, 77–82.Google Scholar
Fox, T. A. & West, G. S. 1993 Fluid-induced loading of cantilevered circular cylinders in a low-turbulence uniform flow. Part 1: mean loading with aspect ratios in the range 4 to 30. J. Fluids Struct. 7 (1), 1–14.CrossRefGoogle Scholar
Frederich, O., Wassen, E. & Thiele, F. 2008 Prediction of the flow around a short wall-mounted finite cylinder using LES and DES. J. Numer. Anal. Ind. Appl. Maths 3 (3–4), 231–247.Google Scholar
Hain, R., Kähler, C. J. & Michaelis, D. 2008 Tomographic and time resolved PIV measurements on a finite cylinder mounted on a flat plate. Exp. Fluids 45 (4), 715–724.CrossRefGoogle Scholar
Kawamura, T., Hiwada, M., Hibino, T., Mabuchi, I. & Kumada, M. 1984 Flow around a finite circular cylinder on a flat plate: cylinder height greater than turbulent boundary layer thickness. Bull. JSME 27 (232), 2142–2151.CrossRefGoogle Scholar
Kitagawa, T., Fujino, Y., Kimura, K. & Mizuno, Y. 2002 Wind pressures measurement on end-cell-induced vibration of a cantilevered circular cylinder. J. Wind Engng Ind. Aerodyn. 90 (4–5), 395–405.CrossRefGoogle Scholar
Lee, L. & Wang, Y. 1987 Aerodynamics of a circular cylinder of finite length in cross flow. In Forum on Turbulent Flows–1987, Cincinnati, OH, pp. 61–65. ASME.Google Scholar
Morton, C., Martinuzzi, R. J., Kindree, M., Shahroodi, M. & Saeedi, M. 2018 Wake dynamics of a cantilevered circular cylinder of aspect ratio 4. Intl J. Heat Fluid Flow 72, 109–122.CrossRefGoogle Scholar
Okamoto, S. & Sunabashiri, Y. 1992 Vortex shedding from a circular-cylinder of finite length placed on a ground plane. J. Fluids Eng. 114 (4), 512–521.CrossRefGoogle Scholar
Okamoto, T. & Yagita, M. 1973 The experimental investigation on the flow past a circular cylinder of finite length placed normal to the plane surface in a uniform stream. Bull. JSME 16 (95), 805–814.CrossRefGoogle Scholar
Palau-Salvador, G., Stoesser, T., Fröhlich, J., Kappler, M. & Rodi, W. 2010 Large eddy simulations and experiments of flow around finite-height cylinders. Flow Turbul. Combust. 84 (2), 239.CrossRefGoogle Scholar
Park, C. W. & Lee, S. J. 2000 Free end effects on the near wake flow structure behind a finite circular cylinder. J. Wind Engng Ind. Aerodyn. 88 (2–3), 231–246.CrossRefGoogle Scholar
Park, C. W. & Lee, S. J. 2002 Flow structure around a finite circular cylinder embedded in various atmospheric boundary layers. Fluid Dyn. Res. 30 (4), 197.CrossRefGoogle Scholar
Park, C. W. & Lee, S. J. 2004 Effects of free-end corner shape on flow structure around a finite cylinder. J. Fluids Struct. 19 (2), 141–158.CrossRefGoogle Scholar
Pattenden, R. J., Turnock, S. R. & Zhang, X. 2005 Measurements of the flow over a low-aspect-ratio cylinder mounted on a ground plane. Exp. Fluids 39 (1), 10–21.CrossRefGoogle Scholar
Prassad, A. & Williamson, C. H. K. 1997 The insability of the shear layer separating from a bluff body. J. Fluid Mech. 333, 375–402.CrossRefGoogle Scholar
Roh, S. C. & Park, S. O. 2001 Surface flow pattern and local mass transfer on the free-end surface of a finite circular cylinder. Heat Mass Transfer 38 (1–2), 1–5.Google Scholar
Roh, S. & Park, S. 2003 Vortical flow over the free end surface of a finite circular cylinder mounted on a flat plate. Exp. Fluids 34 (1), 63–67.CrossRefGoogle Scholar
Roshko, A. 1993 Perspectives on bluff body aerodynamics. J. Wind Engng Ind. Aerodyn. 49 (1–3), 79–100.CrossRefGoogle Scholar
Rostamy, N., Sumner, D., Bergstrom, D. J. & Bugg, J. D. 2012 Local flow field of a surface-mounted finite circular cylinder. J. Fluids Struct. 34, 105–122.CrossRefGoogle Scholar
Sakamoto, H. & Arie, M. 1983 Vortex shedding from a rectangular prism and a circular cylinder placed vertically in a turbulent boundary layer. J. Fluid Mech. 126, 147–165.CrossRefGoogle Scholar
Sciacchitano, A. & Wieneke, B. 2016 PIV uncertainty propagation. Meas. Sci. Technol. 27 (8), 084006.CrossRefGoogle Scholar
Smith, D. R 2002 Interaction of a synthetic jet with a crossflow boundary layer. AIAA J. 40 (11), 2277–2288.CrossRefGoogle Scholar
Sumner, D. 2013 Flow above the free end of a surface-mounted finite-height circular cylinder: a review. J. Fluids Struct. 43, 41–63.CrossRefGoogle Scholar
Sumner, D. & Heseltine, J. L. 2008 Tip vortex structure for a circular cylinder with a free end. J. Wind Engng Ind. Aerodyn. 96 (6–7), 1185–1196.CrossRefGoogle Scholar
Sumner, D., Heseltine, J. L. & Dansereau, O. J. P. 2004 Wake structure of a finite circular cylinder of small aspect ratio. Exp. Fluids 37 (5), 720–730.CrossRefGoogle Scholar
Tanaka, S. & Murata, S. 1999 An investigation of the wake structure and aerodynamic characteristics of a finite circular cylinder: time-averaged wake structures behind circular cylinders with various aspect ratios. JSME Intl J. Ser. B 42 (2), 178–187.CrossRefGoogle Scholar
Tsutsui, T. & Kawahara, M. 2006 Heat transfer around a cylindrical protuberance mounted in a plane turbulent boundary layer. J. Heat Transfer 128 (2), 153–161.CrossRefGoogle Scholar
Uematsu, Y., Yamada, M. & Ishii, K. 1990 Some effects of free-stream turbulence on the flow past a cantilevered circular cylinder. J. Wind Engng Ind. Aerodyn. 33 (1–2), 43–52.CrossRefGoogle Scholar
Wang, H. F. & Zhou, Y. 2009 The finite-length square cylinder near wake. J. Fluid Mech. 638 (2009), 453–490.CrossRefGoogle Scholar
Wang, H. F., Zhou, Y. & Mi, J. 2012 Effects of aspect ratio on the drag of a wall-mounted finite-length cylinder in subcritical and critical regimes. Exp. Fluids 53 (2), 423–436.CrossRefGoogle Scholar
Zhu, H. Y., Wang, C. Y., Wang, H. P. & Wang, J. J. 2017 Tomographic PIV investigation on 3D wake structures for flow over a wall-mounted short cylinder. J. Fluid Mech. 831, 743–778.CrossRefGoogle Scholar