Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-19T16:41:25.576Z Has data issue: false hasContentIssue false

A numerical study of global frequency selection in the time-mean wake of a circular cylinder

Published online by Cambridge University Press:  04 February 2010

J. S. LEONTINI*
Affiliation:
Fluids Laboratory for Aeronautical and Industrial Research (FLAIR), Department of Mechanical Engineering, Monash University, Melbourne, Victoria 3800, Australia Division of Biological Engineering, Monash University, Melbourne, Victoria 3800, Australia
M. C. THOMPSON
Affiliation:
Fluids Laboratory for Aeronautical and Industrial Research (FLAIR), Department of Mechanical Engineering, Monash University, Melbourne, Victoria 3800, Australia Division of Biological Engineering, Monash University, Melbourne, Victoria 3800, Australia
K. HOURIGAN
Affiliation:
Fluids Laboratory for Aeronautical and Industrial Research (FLAIR), Department of Mechanical Engineering, Monash University, Melbourne, Victoria 3800, Australia Division of Biological Engineering, Monash University, Melbourne, Victoria 3800, Australia
*
Email address for correspondence: [email protected]

Abstract

A series of direct numerical simulations, both in two- and three-dimensions, of the flow past a circular cylinder for Reynolds numbers Re ≤ 600 has been conducted. From these simulations, the time-mean (and, for the three-dimensional simulations, the spanwise spatial-mean) flow has been calculated. A global linear stability analysis has been conducted on these mean flows, showing that the mean cylinder wake for Re ≤ 600 is marginally stable and the eigenfrequency of the leading global mode closely predicts the eventual saturated vortex shedding frequency. A local stability analysis has also been conducted. For this, a series of streamwise velocity profiles has been extracted from the mean wake and the stability of these profiles has been analysed using the Rayleigh stability equation. The real and imaginary instability frequencies gained from these profiles have then been used to find the global frequency selected by the flow using a saddle-point criterion. The results confirm the success of the saddle-point criterion when the mean flow is quasi-parallel in the vicinity of the saddle point; however, the limitations of the method when the mean flow exhibits higher curvature are also elucidated.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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

Barkley, D. 2006 Linear analysis of the cylinder wake mean flow. Europhys. Lett. 75 (5), 750756.CrossRefGoogle Scholar
Barkley, D. & Henderson, R. D. 1996 Three-dimensional Floquet stability analysis of the wake of a circular cylinder. J. Fluid Mech. 322, 215241.CrossRefGoogle Scholar
Blackburn, H. M. & Lopez, J. M. 2003 On three-dimensional quasi-periodic Floquet instabilities of two-dimensional bluff body wakes. Phys. Fluids 15, L57L60.CrossRefGoogle Scholar
Chomaz, J. M. 2005 Global instabilities in spatially developing flows: non-normality and nonlinearity. Annu. Rev. Fluid Mech. 37, 357392.CrossRefGoogle Scholar
Drazin, P. G. & Reid, W. H. 2004 Hydrodynamic Stability, 2nd edn. Cambridge University Press.CrossRefGoogle Scholar
Hammond, D. & Redekopp, L. 1997 Global dynamics of symmetric and asymmetric wakes. J. Fluid Mech. 331, 231260.CrossRefGoogle Scholar
Henderson, R. 1997 Nonlinear dynamics and pattern formation in turbulent wake transition. J. Fluid Mech. 352, 65112.CrossRefGoogle Scholar
Huerre, P. & Monkewitz, P. A. 1985 Absolute and convective instabilities in free shear layers. J. Fluid Mech. 159, 151168.CrossRefGoogle Scholar
Huerre, P. & Rossi, M. 1998 Hydrodynamic instabilities in open flows. In Hydrodynamics and Nonlinear Instabilities (ed. Godrèche, C. & Manneville, P.), pp. 81294. Cambridge University Press.CrossRefGoogle Scholar
Khor, M., Sheridan, J. & Hourigan, K. 2008 a The response of the shear layer separating from a circular cylinder to acoustic perturbation. J. Fluid Mech. 601, 425441.CrossRefGoogle Scholar
Khor, M., Sheridan, J., Thompson, M. C. & Hourigan, K. 2008 b Global frequency selection in the observed time-mean wakes of circular cylinders. J. Fluid Mech. 601, 425441.CrossRefGoogle Scholar
Kupfer, K., Bers, A. & Ram, A. K. 1987 The cusp map in the complex-frequency plane for absolute instabilities. Phys. Fluids 30 (10), 30753082.CrossRefGoogle Scholar
Le Dizès, S., Huerre, P., Chomaz, J. M. & Monkewitz, P. A. 1996 Linear global modes in spatially developing media. Phil. Trans. Roy. Soc. Lond. 354, 169212.Google Scholar
Leontini, J. S., Thompson, M. C. & Hourigan, K. 2007 Three-dimensional transition in the wake of a transversely oscillating cylinder. J. Fluid Mech. 577, 79104.CrossRefGoogle Scholar
Monkewitz, P. A. & Nguyen, L. N. 1987 Absolute instabilities in the near-wake of two-dimensional bluff bodies. J. Fluids Struct. 1, 165184.CrossRefGoogle Scholar
Pier, B. 2002 On the frequency selection of finite-amplitude vortex shedding in the cylinder wake. J. Fluid Mech. 458, 407417.CrossRefGoogle Scholar
Pier, B. & Huerre, P. 2001 Nonlinear self-sustained structures and fronts in spatially developing wake flows. J. Fluid Mech. 435, 145174.CrossRefGoogle Scholar
Ryan, K., Thompson, M. C. & Hourigan, K. 2005 Three-dimensional transition in the wake of elongated bluff bodies. J. Fluid Mech. 538, 129.CrossRefGoogle Scholar
Schmid, P. & Henningson, D. S. 2001 Stability and Transition in Shear Flows. Springer.CrossRefGoogle Scholar
Sipp, D. & Lebedev, A. 2007 Global stability of base and mean flows: a general approach and its applications to cylinder and open cavity flows. J. Fluid Mech. 593, 333358.CrossRefGoogle Scholar
Thiria, B. & Wesfreid, J. E. 2007 Stability properties of forced wakes. J. Fluid Mech. 579, 137161.CrossRefGoogle Scholar
Thompson, M. C., Hourigan, K. & Sheridan, J. 1996 Three-dimensional instabilities in the wake of a circular cylinder. Exper. Thermal Fluid Sci. 12, 190196.CrossRefGoogle Scholar
Thompson, M. C., Leweke, T. & Williamson, C. H. K. 2001 The physical mechanism of transition in bluff body wakes. J. Fluids Struct. 15, 607616.CrossRefGoogle Scholar
Tuckerman, L. S. & Barkley, D. 2000 Numerical Methods for Bifurcation Problems and Large-scale Dynamical Systems (chap. Bifurcation analysis for timesteppers), pp. 453566. Springer.CrossRefGoogle Scholar
Williamson, C. H. K. 1988 The existence of two stages in the transition to three dimensionality of a cylinder wake. Phys. Fluids 31, 31653168.CrossRefGoogle Scholar
Williamson, C. H. K. 1989 Oblique and parallel modes of vortex shedding in the wake of a circular cylinder at low Reynolds numbers. J. Fluid Mech. 206, 579627.CrossRefGoogle Scholar