François Daviaud

TL;DR: The observation of dynamo action in the von Kármán sodium experiment, i.e., the generation of a magnetic field by a strongly turbulent swirling flow of liquid sodium, is reported.

TL;DR: In this article, the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium was reported, where the magnetic field randomly switches between two symmetric solutions B and -B.

TL;DR: Experimental evidence of a global bifurcation on a highly turbulent von Kármán flow is reported and the role of turbulence is discussed in two ways: the multiplicity of hydrodynamical solutions and the effect of fluctuations on the nature of transitions.

TL;DR: In this paper, the plane Couette flow, a shear flow linearly stable for all values of the Reynolds number, is experimentally studied and a finite amplitude perturbation, local in time and space, is created in order to desstabilize the flow.

TL;DR: In this article, the plane Couette flow undergoes a globally subcritical transition to turbulence, and the lifetime histograms of patches quenched in the range R[Ru,Rc] display a well-defined exponentially decreasing tail.