Global mode of a sphere turbulent wake controlled by a small sphere

Abstract : A small control sphere is displaced in a cross flow plane downstream of a main sphere of diameter D in a uniform flow at Re = 33000. The wake is studied by means of 4 fixed hot wire probes. It is shown that without the control sphere (reference case), vortex loops are shed from only one side of the sphere at a Strouhal number St = 0.19. This reference wake structure has a planar symmetry defining an azimuthal phase θ W that is observed to be random in time. The secondary smaller sphere is treated as a local disturbance of the reference wake. It is found that the shedding occurs closer to the symmetry axis for the control sphere placed at the center of the wake than for the natural case. When the control sphere is off-centered, a subharmonic at half the natural frequency appears and the azimuthal phase becomes imposed by the control sphere position. A pure subharmonic mode is observed when the control sphere reaches the separated shear, suggesting alternative vortex loops shedding from both sides of the wake.
Type de document :
Article dans une revue
Journal of Fluids and Structures, Elsevier, 2013, 〈10.1016/j.jfluidstructs.2013.02.022〉
Liste complète des métadonnées

Littérature citée [22 références]  Voir  Masquer  Télécharger
Contributeur : Olivier Cadot <>
Soumis le : jeudi 12 novembre 2015 - 17:28:33
Dernière modification le : mercredi 20 décembre 2017 - 11:34:06
Document(s) archivé(s) le : vendredi 28 avril 2017 - 08:26:06


Fichiers produits par l'(les) auteur(s)




G Vilaplana, M Grandemange, M Gohlke, Olivier Cadot. Global mode of a sphere turbulent wake controlled by a small sphere. Journal of Fluids and Structures, Elsevier, 2013, 〈10.1016/j.jfluidstructs.2013.02.022〉. 〈hal-01228159〉



Consultations de la notice


Téléchargements de fichiers