Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-06-19T22:37:40.387Z Has data issue: false hasContentIssue false
  • English
  • Français

Forcing symmetry exchanges and flow reversals in turbulent wakes

Published online by Cambridge University Press:  14 September 2017

Diogo Barros Open the ORCID record for Diogo Barros [Opens in a new window] ,
Jacques Borée ,
Olivier Cadot Open the ORCID record for Olivier Cadot [Opens in a new window] ,
Andreas Spohn  and
Bernd R. Noack Open the ORCID record for Bernd R. Noack [Opens in a new window]
Diogo Barros
Affiliation:
Institut Pprime UPR-3346, CNRS – Université de Poitiers – ENSMA, Poitiers 86360, France
Jacques Borée
Affiliation:
Institut Pprime UPR-3346, CNRS – Université de Poitiers – ENSMA, Poitiers 86360, France
Olivier Cadot
Affiliation:
IMSIA, ENSTA–ParisTech/CNRS/CEA/EDF, Université Paris Saclay, Palaiseau 91762, France
Andreas Spohn
Affiliation:
Institut Pprime UPR-3346, CNRS – Université de Poitiers – ENSMA, Poitiers 86360, France
Bernd R. Noack
Affiliation:
LIMSI – CNRS UPR 3251, Campus Universitaire d’Orsay, Orsay 91405, France Institut für Strömungsmechanik, TU Braunschweig, Braunschweig 38108, Germany
Get access Rights & Permissions [Opens in a new window]

Abstract

Turbulent wakes past bluff bodies commonly present asymmetric flow states reminiscent of bifurcations in the laminar regime. Understanding the sensitivity of these states to flow forcing is crucial to the modelling and control of flow symmetry properties. In this study, the near wake of a rectangular bluff body in proximity to a wall is disturbed by the use of passive devices located between the model and the wall, upstream of the massive flow separation occurring at the blunt trailing edges. Due to the proximity to the boundary, the wake initially presents wall-normal asymmetry and a negative wall-normal pressure gradient along the base. The application of disturbances with variable size, however, sets flow symmetry along the wall-normal plane, leading to the intermittent spanwise wake reversals reported recently in the literature. A further increase in the size of perturbation suppresses wake switching, and wall-normal asymmetry is recovered, but with a positive wall-normal pressure gradient. The dynamical features of this bifurcation scenario can be retrieved using two coupled symmetry-breaking models for spanwise and wall-normal pressure gradients. This confirms the high sensitivity of the separated flow to external perturbations. More importantly, the results unify observations of the bluff-body wake topologies covered in previous investigations.

JFM classification

Nonlinear Dynamical Systems: Bifurcation Flow Control: Instability control Wakes/Jets: Wakes
Type
Rapids
Information
Journal of Fluid Mechanics , Volume 829 , 25 October 2017 , R1
Check for updates
Copyright
© 2017 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

Achenbach, E. 1974 Vortex shedding from spheres. J. Fluid Mech. 62 (02), 209–221.CrossRefGoogle Scholar
Ahmed, S. R., Ramn, G. & Faltin, G.1984 Some salient features of the time averaged ground vehicle wake. SAE Tech. Rep. No. 840300, Society of Automotive Engineers, Inc., Warrendale, PA.CrossRefGoogle Scholar
Barros, D., Borée, J., Noack, B. R. & Spohn, A. 2016a Resonances in the forced turbulent wake past a 3D blunt body. Phys. Fluids 28 (6), 065104.CrossRefGoogle Scholar
Barros, D., Borée, J., Noack, B. R., Spohn, A. & Ruiz, T. 2016b Bluff body drag manipulation using pulsed jets and Coanda effect. J. Fluid Mech. 805, 422–459.CrossRefGoogle Scholar
Brackston, R. D., de la Cruz Lopez, J. M. G., Wynn, A., Rigas, G. & Morrison, J. F. 2016 Stochastic modelling and feedback control of bistability in a turbulent bluff body wake. J. Fluid Mech. 802, 726–749.CrossRefGoogle Scholar
Choi, H., Lee, J. & Park, H. 2014 Aerodynamics of heavy vehicles. Annu. Rev. Fluid Mech. 46, 441–468.CrossRefGoogle Scholar
Evrard, A., Cadot, O., Herbert, V., Ricot, D., Vigneron, R. & Délery, J. 2016 Fluid force and symmetry breaking modes of a 3D bluff body with a base cavity. J. Fluids Struct. 61, 99–114.CrossRefGoogle Scholar
Evstafyeva, O., Morgans, A. S. & Dalla Longa, L. 2017 Simulation and feedback control of the Ahmed body flow exhibiting symmetry breaking behaviour. J. Fluid Mech. 817, R2.CrossRefGoogle Scholar
Fabre, D., Auguste, F. & Magnaudet, J. 2008 Bifurcations and symmetry breaking in the wake of axisymmetric bodies. Phys. Fluids 20 (5), 051702.CrossRefGoogle Scholar
Gardiner, C. W. 1985 Handbook of Stochastic Methods. Springer.Google Scholar
Gentile, V., van Oudheusden, B. W., Schrijer, F. F. J. & Scarano, F. 2017 The effect of angular misalignment on low-frequency axisymmetric wake instability. J. Fluid Mech. 813, R3.CrossRefGoogle Scholar
Grandemange, M., Cadot, O. & Gohlke, M. 2012 Reflectional symmetry breaking of the separated flow over three-dimensional bluff bodies. Phys. Rev. E 86 (3), 035302.Google ScholarPubMed
Grandemange, M., Gohlke, M. & Cadot, O. 2013a Bi-stability in the turbulent wake past parallelepiped bodies with various aspect ratios and wall effects. Phys. Fluids 25 (9), 095103.CrossRefGoogle Scholar
Grandemange, M., Gohlke, M. & Cadot, O. 2013b Turbulent wake past a three-dimensional blunt body. Part 1. Global modes and bi-stability. J. Fluid Mech. 722, 51–84.CrossRefGoogle Scholar
Grandemange, M., Gohlke, M. & Cadot, O. 2014 Statistical axisymmetry of the turbulent sphere wake. Exp. Fluids 55 (11), 1–11.CrossRefGoogle Scholar
Kloeden, P. & Platen, E. 1992 Numerical Solution of Stochastic Differential Equations. Springer.CrossRefGoogle Scholar
Krajnovic, S. & Davidson, L. 2003 Numerical study of the flow around a bus-shaped body. Trans. ASME J. Fluids Engng 125 (3), 500–509.CrossRefGoogle Scholar
Lahaye, A., Leroy, A. & Kourta, A. 2014 Aerodynamic characterisation of a square back bluff body flow. Int. J. Aerod. 4 (1–2), 43–60.Google Scholar
Li, R., Barros, D., Borée, J., Cadot, O., Noack, B. R. & Cordier, L. 2016 Feedback control of bimodal wake dynamics. Exp. Fluids 57 (10), 158.CrossRefGoogle Scholar
Marquet, O. & Larsson, M. 2015 Global wake instabilities of low aspect-ratio flat-plates. Eur. J. Mech. (B/Fluids) 49, 400–412.CrossRefGoogle Scholar
McArthur, D., Burton, D., Thompson, M. & Sheridan, J. 2016 On the near wake of a simplified heavy vehicle. J. Fluids Struct. 66, 293–314.CrossRefGoogle Scholar
Perry, A. K., Pavia, G. & Passmore, M. 2016 Influence of short rear end tapers on the wake of a simplified square-back vehicle: wake topology and rear drag. Exp. Fluids 57 (11), 169.CrossRefGoogle Scholar
Rigas, G., Morgans, A. S., Brackston, R. D. & Morrison, J. F. 2015 Diffusive dynamics and stochastic models of turbulent axisymmetric wakes. J. Fluid Mech. 778, R2.CrossRefGoogle Scholar
Rigas, G., Oxlade, A. R., Morgans, A. S. & Morrison, J. F. 2014 Low-dimensional dynamics of a turbulent axisymmetric wake. J. Fluid Mech. 755, R5.CrossRefGoogle Scholar
Sreenivasan, K. R., Bershadskii, A. & Niemela, J. J. 2002 Mean wind and its reversal in thermal convection. Phys. Rev. E 65 (5), 056306.Google ScholarPubMed
de la Torre, A. & Burguete, J. 2007 Slow dynamics in a turbulent von Kármán swirling flow. Phys. Rev. Lett. 99 (5), 054101.CrossRefGoogle Scholar
Varon, E., Eulalie, Y., Edwige, S., Gilotte, P. & Aider, J. L. 2017 Chaotic dynamics of large-scale structures in a turbulent wake. Phys. Rev. Fluids 2 (3), 034604.CrossRefGoogle Scholar
Volpe, R., Devinant, P. & Kourta, A. 2015 Experimental characterization of the unsteady natural wake of the full-scale square back Ahmed body: flow bi-stability and spectral analysis. Exp. Fluids 56 (5), 1–22.CrossRefGoogle Scholar
Wassen, E., Eichinger, S. & Thiele, F. 2010 Simulation of active drag reduction for a square-back vehicle. In Active Flow Control II, pp. 241–255. Springer.CrossRefGoogle Scholar