Optimal velocity and density profiles for the onset of absolute instability in jets

Lutz Lesshafft 1, * Olivier Marquet 2
* Auteur correspondant
1 LadHyX - Laboratoire d'hydrodynamique
2 Meudon - ONERA - The French Aerospace Lab
Abstract : The absolute/convective character of the linear instability of axisymmetric jets is investigated for a wide range of parallel velocity and density profiles. An adjoint-based sensitivity analysis is carried out in order to maximize the absolute growth rate of jet profiles with and without density variations. It is demonstrated that jets without counterflow may display absolute instability at density ratios well above the previously assumed threshold rho(jet)/rho(infinity) = 0.72, and even in homogeneous settings. Absolute instability is promoted by a strong velocity gradient in the low-velocity region of the shear layer, as well as by a step-like density variation near the location of maximum shear. A new efficient algorithm for the computation of the absolute instability mode is presented.
Type de document :
Article dans une revue
Journal of Fluid Mechanics, Cambridge University Press (CUP), 2010, 662 (November), pp.398-408. 〈10.1017/s0022112010004246〉
Liste complète des métadonnées

Littérature citée [12 références]  Voir  Masquer  Télécharger
https://hal-polytechnique.archives-ouvertes.fr/hal-01020674
Contributeur : Denis Roura <>
Soumis le : mercredi 9 juillet 2014 - 10:52:52
Dernière modification le : mercredi 25 avril 2018 - 10:45:03
Document(s) archivé(s) le : jeudi 9 octobre 2014 - 10:45:31

Fichier

OVS0022112010004246a.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

Collections

X-LADHYX | X | PARISTECH | ONERA

Citation

Lutz Lesshafft, Olivier Marquet. Optimal velocity and density profiles for the onset of absolute instability in jets. Journal of Fluid Mechanics, Cambridge University Press (CUP), 2010, 662 (November), pp.398-408. 〈10.1017/s0022112010004246〉. 〈hal-01020674〉

Exporter

BibTeX TEI DC DCterms EndNote

Partager

Métriques

Consultations de la notice

146

Téléchargements de fichiers

275

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD