European Turbulence Conference 2015

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16:45
15 mins

Slow Dynamics in turbulent Helium flows
Javier Burguete, Philippe Roche, Bernard Rousset

Session: Instability and Transition 6
Session starts: Thursday 27 August, 15:00
Presentation starts: 16:45
Room: Room A

Javier Burguete (University of Navarra)
Philippe Roche (Institut Néel, CNRS)
Bernard Rousset (SBT, CEA Grenoble)

Abstract:
The presence of slow dynamics is a recurrent feature of many turbulent flows. This behaviour can be created by instabilities of the mean flow or by other mechanisms. In this work we analyze the behavior of a highly turbulent Helium flow (maximum Reynolds number Re=10^8, with a Reynolds based on the Taylor microscale Re_\lambda=2000). We have performed velocity measurements using home-made Pitot tubes. The analysis of the data series reveals that below the injection frequencies there are different dynamical regimes with time scales two orders of magnitude below the injection scale