Slow Dynamics in turbulent Helium flows etc15 Tracking Number 473Presentation: Session: Instability and Transition 6 Room: Room A Session start: 15:00 Thu 27 Aug 2015 Javier Burguete javier@unav.es Affifliation: University of Navarra Philippe Roche philippe.roche@grenoble.cnrs.fr Affifliation: Institut Néel, CNRS Bernard Rousset bernard.rousset@cea.fr Affifliation: SBT, CEA Grenoble Topics: - Instability and transition, - Vortex dynamics and structure formation, - Turbulence in superfluids 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 |