Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-18T02:22:11.126Z Has data issue: false hasContentIssue false

Towards a quantitative comparison between global and local stability analysis

Published online by Cambridge University Press:  18 April 2017

L. Siconolfi
Affiliation:
DICI, Università di Pisa, Via Girolamo Caruso, 56122 Pisa, Italy
V. Citro
Affiliation:
DIIN, Universitá degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy
F. Giannetti*
Affiliation:
DIIN, Universitá degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy
S. Camarri
Affiliation:
DICI, Università di Pisa, Via Girolamo Caruso, 56122 Pisa, Italy
P. Luchini
Affiliation:
DIIN, Universitá degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy
*
Email address for correspondence: fgiannetti@unisa.it

Abstract

A methodology is proposed here to estimate the stability characteristics of bluff-body wakes using local analysis under the assumption of weakly non-parallel flows. In this connection, a generalisation of the classic spatio-temporal stability analysis for fully three-dimensional flows is first described. Secondly, an additional higher-order correction term with respect to the common saddle-point global frequency estimation is included in the analysis. The proposed method is first validated for the case of the flow past a circular cylinder and then applied to two fully three-dimensional flows: the boundary layer flow over a wall-mounted hemispherical body and the wake flow past a fixed sphere. In all the cases considered, both the estimated unstable eigenvalue and the spatial shape of the associated eigenmode are determined by local stability analysis, and they are compared with the reference counterparts obtained at a definitely higher computational cost by a fully three-dimensional global stability analysis. It is shown that the results of local stability analysis, when the higher-order correction term is included, are in excellent agreement with those obtained by global stability analysis. It is also shown that the retained correction term is of crucial importance in this perspective, leading to a remarkable improvement in accuracy with respect to the classical saddle-point estimation.

Type
Papers
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

Bender, C. M. & Orszag, S. A. 1978 Advanced Mathematical Methods for Scientists and Engineers. McGraw-Hill.Google Scholar
Bers, A. 1983 Space–time evolution of plasma instabilities-absolute and convective. In Handbook of Plasma Physics, vol. 1, pp. 451517. McGraw-Hill.Google Scholar
Briggs, J. 1964 Electron–Stream Interaction with Plasmas. MIT Press.CrossRefGoogle Scholar
Chomaz, J. M., Huerre, P. & Redekopp, L. G. 1988 Bifurcations to local and global modes in spatially developing flows. Phys. Rev. Lett. 60, 2528.Google Scholar
Citro, V., Giannetti, F., Luchini, P. & Auteri, F. 2015 Global stability and sensitivity analysis of boundary-layer flows past a hemispherical roughness element. Phys. Fluids 27, 084110.Google Scholar
Citro, V., Tchoufag, J., Fabre, D., Giannetti, F. & Luchini, P. 2016 Linear stability and weakly nonlinear analysis of the flow past rotating spheres. J. Fluid Mech. 807, 6286.Google Scholar
Cooper, A. J. & Crighton, D. G. 2000 Global modes and superdirective acoustic radiation in low-speed axisymmetrics jets. Eur. J. Mech. (B/Fluids) 19, 559574.CrossRefGoogle Scholar
Giannetti, F. & Luchini, P. 2006 Leading-edge receptivity by adjoint methods. J. Fluid Mech. 547, 2153.Google Scholar
Giannetti, F. & Luchini, P. 2007 Structural sensitivity of the first instability of the cylinder wake. J. Fluid Mech. 581, 167197.Google Scholar
Huerre, P. & Monkewitz, P. A. 1985 Absolute and convective instabilities in free shear layers. J. Fluid Mech. 159, 151168.Google Scholar
Huerre, P. & Monkewitz, P. A. 1990 Local and global instabilities in spatially developing flows. Annu. Rev. Fluid Mech. 22, 473537.Google Scholar
Huerre, P. & Rossi, M. 1998 Hydrodynamics instabilities in open flows. In Hydrodynamics and Nonlinear Instabilities, Cambridge University Press.Google Scholar
Juniper, M. P. & Pier, B. 2015 The structural sensitivity of open shear flows calculated with a local stability analysis. Eur. J. Mech. (B/Fluids) 49, 426437.Google Scholar
Juniper, M. P., Tammisola, O. & Lundell, F. 2011 The local and global stability of confined planar wakes at intermediate reynolds number. J. Fluid Mech. 686, 218238.Google Scholar
Lashgari, I., Tammisola, O., Citro, V., Brandt, L. & Juniper, M. P. 2014 The planar x-junction flow: stability and control. J. Fluid Mech. 753, 128.Google Scholar
Monkewitz, P. A., Huerre, P. & Chomaz, J. M. 1993 Global linear stability analysis of weakly non-parallel shear flows. J. Fluid Mech. 251, 120.Google Scholar
Pier, B. 2002 On the frequency selection of finite-amplitude vortex shedding in the cylinder wake. J. Fluid Mech. 458, 407417.Google Scholar
Pier, B. 2008 Local and global instabilities in the wake of a sphere. J. Fluid Mech. 603, 3961.Google Scholar
Pier, B. & Huerre, P. 2001 Nonlinear self-sustained structures and fronts in spatially developing wake flows. J. Fluid Mech. 435, 145174.Google Scholar
Pier, B., Huerre, P., Chomaz, J. M. & Couairon, A. 1998 Steep nonlinear global modes in spatially developing media. Phys. Fluids 10, 24332435.CrossRefGoogle Scholar
Tammisola, O., Giannetti, F., Citro, V. & Juniper, M. P. 2014 Second-order perturbation of global modes and implications for spanwise wavy actuation. J. Fluid Mech. 755, 314335.Google Scholar
Theofilis, V. 2011 Global linear instability. Annu. Rev. Fluid Mech. 43, 319352.Google Scholar
Zuccher, S. & Luchini, P. 2014 Boundary-layer receptivity to external disturbances using multiple scales. Meccanica 49, 441467.Google Scholar