Hostname: page-component-6b989bf9dc-wj8jn Total loading time: 0 Render date: 2024-04-14T22:50:46.666Z Has data issue: false hasContentIssue false
  • English
  • Français

The role of separation on the forces acting on a circular cylinder with a control rod

Published online by Cambridge University Press:  11 March 2021

M.M. Cicolin Open the ORCID record for M.M. Cicolin [Opens in a new window] ,
O.R.H. Buxton Open the ORCID record for O.R.H. Buxton [Opens in a new window] ,
G.R.S. Assi Open the ORCID record for G.R.S. Assi [Opens in a new window]  and
P.W. Bearman
M.M. Cicolin*
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK Escola Politécnica, University of São Paulo, Brazil
O.R.H. Buxton
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK
G.R.S. Assi
Affiliation:
Escola Politécnica, University of São Paulo, Brazil
P.W. Bearman
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK
*
†Email address for correspondence: mmcicolin@gmail.com
Get access Rights & Permissions [Opens in a new window]

Abstract

The development of the flow around a circular cylinder with a smaller diameter control rod in close proximity is the subject of this paper. It has long been known that this is an effective way to attenuate regular vortex shedding leading to reductions in its adverse effects on bluff-body flow. The aim of this study is to improve understanding of the ways the control rod affects the near-wake flow including how it influences the positions of boundary layer separation. Experiments were carried out in a water channel to measure lift and drag forces and particle image velocimetry (PIV) was employed to obtain detailed information on flow structure. The values of important properties were fixed as follows: Reynolds number, 20 000; ratio of cylinder and control rod diameters, 10 : 1; centre-to-centre distance between main cylinder and control rod, 0.7$D$ (where $D$ is the main cylinder diameter). The adjustable parameter was the angular position of the rod, $\theta$, which was varied between $90^{\circ }$ and $180^{\circ }$ from the front stagnation line. Lift and drag forces were measured separately for the main cylinder and the control rod. A new method for identifying flow states is introduced using PIV to interrogate the instantaneous flow velocity in the gap between the main cylinder and the control rod. Similarly to previous studies, three stable flow states were observed together with a bistable state. The bistable state is very sensitive to the control rod angle with a small change of ${\pm }1^{\circ }$ being sufficient to change the flow state.

JFM classification

Wakes/Jets: Vortex streets Vortex Flows: Vortex shedding
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 915 , 25 May 2021 , A33
Check for updates
Copyright
© The Author(s), 2021. 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.)

References

REFERENCES

Baj, P., Bruce, P.J.K. & Buxton, O.R.H. 2015 The triple decomposition of a fluctuating velocity field in a multiscale flow. Phys. Fluids 27, 075104.Google Scholar
Baj, P. & Buxton, O.R.H. 2017 Interscale energy transfer in the merger of wakes of a multiscale array of rectangular cylinders. Phys. Rev. Fluids 2, 114607.CrossRefGoogle Scholar
Bearman, P.W. 1984 Vortex shedding from oscillating bluff bodies. Annu. Rev. Fluid Mech. 16, 195–222.CrossRefGoogle Scholar
Bingham, C., Morton, C. & Martinuzzi, R.J. 2018 a Influence of control cylinder placement on vortex shedding from a circular cylinder. Exp. Fluids 59, 158.CrossRefGoogle Scholar
Bingham, C., Raibaudo, C., Morton, C. & Martinuzzi, R.J. 2018 b Suppression of fluctuating lift on a cylinder via evolutionary algorithms: control with interfering small cylinder. Phys. Fluids 30, 127104.Google Scholar
Choi, H., Jeon, W.P. & Kim, J. 2008 Control of flow over a bluff body. Annu. Rev. Fluid Mech. 40, 113–139.Google Scholar
Cicolin, M.M., Serson, D., Assi, G.R.S. & Meneghini, J.R. 2018 Experimental and numeric study of the control of flow over a circular cylinder using control rods. In 7th Conference on Bluff Body Wakes and Vortex-Induced Vibrations (ed. T. Leweke & C.H.K. Williamson).Google Scholar
Dalton, C., Xu, Y. & Owen, J.C. 2001 The suppresion of lift on a circular cylinder due to vortex shedding at moderate reynolds numbers. J. Fluids Struct. 15, 617–628.CrossRefGoogle Scholar
Dipankar, A., Sengupta, T.K. & Talla, S.B. 2007 Suppression of vortex shedding behind a circular cylinder by another control cylinder at low Reynolds numbers. J. Fluid Mech. 573, 171–190.Google Scholar
Fage, A. & Warsap, J.H. 1929 The effects of turbulence and surface roughness on the drag of a circular cylinder. Tech. Rep. Ae 429. Aeronautical Research Committee, London.Google Scholar
Gerrard, J.H. 1966 The mechanics of the formation region of vortices behind bluff bodies. J. Fluid Mech. 25, 401–413.CrossRefGoogle Scholar
Grandemange, M. 2013 Analysis and control of three-dimensional turbulent wakes: from axismmetric bodies to road vehicles. PhD thesis, ENSTA ParisTech.Google Scholar
Mittal, S. & Raghuvanshi, A. 2001 Control of vortex shedding behind circular cylinder for flows at low Reynolds numbers. Intl J. Numer. Meth. Fluids 35, 421–447.Google Scholar
Norberg, C. 2003 Fluctuating lift on a circular cylinder: review and new measurements. J. Fluids Struct. 17 (1), 57–96.CrossRefGoogle Scholar
Parezanovic, V. & Cadot, O. 2009 The impact of a local perturbation on global properties of a turbulent wake. Phys. Fluids 21, 071071.Google Scholar
Parezanovic, V. & Cadot, O. 2012 Experimental sensitivity analysis of the global properties of a two-dimensional turbulent wake. J. Fluid Mech. 693, 115–149.Google Scholar
Parezanovic, V., Monchaux, R. & Cadot, O. 2015 Characterization of the turbulent bistable flow regime of a 2d bluff body wake disturbed by a small control cylinder. Exp. Fluids 56–12, 1–8.Google Scholar
Reichl, P., Hourigan, K. & Thompson, M.C. 2005 Flow past a cylinder close to a free surface. J. Fluid Mech. 533, 269–296.CrossRefGoogle Scholar
Rodríguez-López, E., Bruce, P.J.K. & Buxton, O.R.H. 2016 Near field development of artificially generated high Reynolds number turbulent boundary layers. Phys. Rev. Fluids 1, 074401.CrossRefGoogle Scholar
Roshko, A. 1954 On the development of turbulent wakes from vortex streets. Tech. Rep. 1191. National Advisory Committee for Aeronautics.Google Scholar
Sakamoto, H. & Haniu, H. 1994 Optimum suppression of fluid forces acting on a circular cylinder. J. Fluids Engng 116, 221–227.Google Scholar
Sakamoto, H., Tan, K. & Haniu, H. 1991 An optimum suppression of fluid forces by controlling a shear layer separated from a square prism. J. Fluids Engng 113, 183–189.Google Scholar
Schmid, P.J. 2010 Dynamic mode decomposition of numerical and experimental data. J. Fluid Mech. 656, 5–28.CrossRefGoogle Scholar
Strykowski, P.J. & Sreenivasan, R. 1990 On the formation and suppression of vortex ‘shedding’ at low Reynolds numbers. J. Fluid Mech. 218, 71–107.Google Scholar
Szepessy, S. & Bearman, P.W. 1992 Aspect ratio and end plate effects on vortex shedding from a circular cylinder. J. Fluid Mech. 234, 191–217.CrossRefGoogle Scholar
Westerweel, J. & Scarano, F. 2005 Universal outlier detection for PIV data. Exp. Fluids 39, 1096–1100.CrossRefGoogle Scholar
Williamson, C.H.K. 1996 Vortex dynamics in the cylinder wake. Annu. Rev. Fluid Mech. 28, 477–539.Google Scholar
Wynn, A., Pearson, D.S., Ganapathisubramani, B. & Goulart, P.J. 2013 Optimal mode decomposition for unsteady flows. J. Fluid Mech. 733, 473–503.Google Scholar
Yildirim, I., Rindt, C.C.M. & Steenhoven, A.A. 2010 Vortex dynamics in a wire-disturbed cylinder wake. Phys. Fluids 22, 094101.CrossRefGoogle Scholar
Zdravkovich, M. 1997 Flow Around Circular Cylinders, I: Fundamentals. Oxford Science Publications.Google Scholar

Cicolin et al. supplementary movie 1

Vortex street past a bare cylinder at Re=20 000.

Download Cicolin et al. supplementary movie 1(Video)
Video 2 MB

Cicolin et al. supplementary movie 2

Typical wake of state I. case θ=90°

Download Cicolin et al. supplementary movie 2(Video)
Video 1.9 MB

Cicolin et al. supplementary movie 3

Typical wake of state II. case θ=120°

Download Cicolin et al. supplementary movie 3(Video)
Video 2 MB

Cicolin et al. supplementary movie 4

Typical wake of state III. case θ=135°

Download Cicolin et al. supplementary movie 4(Video)
Video 2 MB

Cicolin et al. supplementary movie 5

Bi-stable case, θ=130°

Download Cicolin et al. supplementary movie 5(Video)
Video 7.9 MB