Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-19T11:58:58.352Z Has data issue: false hasContentIssue false

Optimal disturbances in swept Hiemenz flow

Published online by Cambridge University Press:  26 April 2007

ALAN GUÉGAN
Affiliation:
Laboratoire d'Hydrodynamique (LadHyX), CNRS-École Polytechnique, F-91128 Palaiseau, France
PATRICK HUERRE
Affiliation:
Laboratoire d'Hydrodynamique (LadHyX), CNRS-École Polytechnique, F-91128 Palaiseau, France
PETER J. SCHMID
Affiliation:
Laboratoire d'Hydrodynamique (LadHyX), CNRS-École Polytechnique, F-91128 Palaiseau, France

Abstract

The initial perturbation with the largest transient energy growth is computed in the context of the swept leading-edge boundary layer. The highest energy amplification is found for perturbations which are homogeneous in the spanwise z-direction, although on shorter time scales the most amplified disturbances have a finite spanwise wavenumber. In both cases the production term associated with the shear of the spanwise velocity is responsible for the energy amplification in the perturbation energy equation. A connection is made with the amplification mechanism exhibited by optimal perturbations in streaky boundary layers (Hoepffner et al. J. Fluid Mech. vol. 537, 2005, p.91) and the results are compared to the optimal Görtler–Hämmerlin disturbances computed by Guégan et al. (J. Fluid Mech. vol. 566, 2006, p. 11).

Type
Papers
Copyright
Copyright © Cambridge University Press 2007

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

REFRENCES

Butler, K. M. & Farrell, B. F. 1992 Three-dimensional optimal perturbations in viscous shear flow. Phys. Fluids A 4, 16371650.CrossRefGoogle Scholar
Corbett, P. & Bottaro, A. 2001 Optimal linear growth in swept boundary layers. J. Fluid Mech. 435, 123.CrossRefGoogle Scholar
Guégan, A., Schmid, P. J. & Huerre, P. 2006 Optimal energy growth and optimal control in swept Hiemenz flow J. Fluid Mech. 566, 1145.CrossRefGoogle Scholar
Hoepffner, J., Brandt, L. & Henningson, D. S. 2005 Transient growth on boundary layer streaks J. Fluid Mech. 537, 91100.CrossRefGoogle Scholar
Hunt, J. C. R., Wray, A. A. & Moin, P. 1988 Eddies, streams, and convergence zones in turbulent flows. In Studying Turbulence Using Numerical Simulation Databases, 2. Proc. of the 1988 Summer Program, pp. 193–208.Google Scholar
Landahl, M. T. 1980 A note on an algebraic instability of inviscid parallel shear flows. J. Fluid Mech. 98, 243251.Google Scholar
Obrist, D. & Schmid, P.J. 2003 a On the linear stability of swept attachment-line boundary layer flow. Part 1. Spectrum and asymptotic behavior. J. Fluid Mech. 493, 129.CrossRefGoogle Scholar
Obrist, D. & Schmid, P. J. 2003 b On the linear stability of swept attachment-line boundary layer flow. Part 2. Non-modal effects and receptivity. J. Fluid Mech. 493, 3158.CrossRefGoogle Scholar
Orr, W. M. F. 1907 The stability or instability of the steady motions of a liquid. Proc. R. Irish Acad. A 27, 969.Google Scholar