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Accueil > Actualités > Séminaires > Séminaires 2016

Jeudi 17 novembre 2016 à 11h00 en salle K118

Christos Vassilicos, Faculty of Engineering, Department of Aeronautics, Imperial College, London

Titre/Title : Unsteady turbulence cascades and their link to entrainment and the T/NT interface.

Contact : Martin Obligado (équipe EDT)

Résumé/Abstract : We identify two different types of unsteady turbulence cascade for 3D incompressible turbulence both of which imply a particular turbulence dissipation scaling. In one case this scaling is the same as the one implied by the Kolmogorov steady cascade, in the other it is not but it appears in a variety of turbulent flows. Turbulence dissipation scalings are closely related to the scalings of the local entrainment velocity $u_e$ of the turbulent/non-turbulent (T/NT) interface in an axisymmetric and self-similar turbulent wake. The turbulence dissipation scaling implied by the Kolmogorov equilibrium cascade is consistent with a Kolmogorov scaling of $u_e$ whereas the different non-equilibrium dissipation scaling present in the case of one of the two types of non-equilibrium cascade is consistent with a different scaling of $u_e$.