Fluctuation-Dissipation Relations and statistical temperatures in a turbulent von Kármán flow
Résumé
We experimentally characterize the fluctuations of the non-homogeneous non-isotropic turbulence in an axisymmetric von Kármán flow. We show that these fluctuations satisfy relations analogous to classical Fluctuation-Dissipation Relations (FDRs) in statistical mechanics. We use these relations to measure statistical temperatures of turbulence. The values of these temperatures are found to be dependent on the considered observable as already evidenced in other far from equilibrium systems.