Laboratoire de Mécanique des Fluides et d'Acoustique - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France


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Accueil > Activités de Recherche > Fluides Complexes et Transferts > Séminaire du groupe > Archives (2017)

le 15 juin 2017 - Gaby LAUNAY
Transition to turbulence of a square flow driven by acoustic streaming.

13h@Salle I11-1, ECL (Écully)

 le 15 juin 2017 - Gaby LAUNAY Transition to turbulence of a square flow driven by acoustic streaming.

The development of less polluting methods for purifying the silica for the photo-voltaic industry necessitates non-intrusive ways of mixing melted silica in furnaces. The acoustic streaming phenomena (generation of velocity through acoustic waves) is a promising way of generating a forcing in silica furnaces without having to introduce mechanical components.

In order to understand more clearly the flows generated by such forcing, as well as their mixing properties, this study focuses on the transition to chaos of a flow generated by increasing acoustic forcing in a square cavity. The flow cases are computed using a spectral numerical code and examined through non-linear time-series analysis.

The results show a complex transition to turbulence, through Hopf bifurcations, pitchfork bifurcations and appearance of intermittence. Moreover, the transition shows a interesting dynamical simplification, apparently linked to the breaking of the mean flow vertical symmetry.


[Gaby LAUNAY] travaille en tant qu’un ATER à l’INSA/LMFA.