Multistability and memory effect in a highly turbulent flow:   experimental evidence for a global bifurcation
  We report an experimental evidence of a global bifurcation on a highly turbulent von Karman flow. The mean flow presents multiple solutions: the canonical symmetric solution becomes marginally unstable towards a flow which breaks the basic symmetry of the driving apparatus even at very large Reynolds number. The global bifurcation between these states is highly subcritical and the system thus keeps a memory of its history. The transition recalls low-dimension dynamical systems transitions and exhibits a very peculiar statistics. We discuss the role of turbulence in two ways: the multiplicity of hydrodynamical solutions and the effect of fluctuations on the nature of transitions. 
Florent Ravelet (SPEC), Louis Marie (SPEC), Arnaud Chiffaudel (SPEC),   Francois Daviaud (SPEC)