The von Kármán flow as a paradigm for out-of-equilibrium statistical physics
type: Dataset
description: This dissertation tries a novel approach of statistical mechanics (at and out of equilibrium) to understand the behaviour of a fully turbulent confined flow --- von Kármán flow --- stirred by two counter-rotating impellers in a cylinder vessel. First, experimental results from speed control are extended using new PIV observations: the susceptibility divergence of the flow is studied similarly to a mean-field Ising model, for which the spatial correlations and the fluctuation-dissipation theorem are examined. Second, additional experimental results obtained in torque control are also detailed, revealing negative differential responses allowing an analogy with other out-of-equilibrium experiments such as electrical dipoles or complex fluids. These results are understood in the framework of ensemble inequivalence, typical of long-range interacting systems. In addition, escape times from attracting states in multi-stable experiments display a Kramers-like simple dynamics, as do systems with few degrees of freedom. Finally, preliminary results from the SHREK experiment are shown: torques measured in normal and superfluid liquid helium exhibit similar results. Moreover, the Reynolds number range achieved in this experiment allows a more thorough study of the evolution of the hysteresis cycle already studied for lower Reynolds numbers.
issued: 2026-05-08T00:49:22.552435
language: fr
modified: 2026-05-08T00:49:22.552439
contact point: Organization
  fn: CCSD
keyword: ecoulement-de-von-karman
keyword: infoeu-reposemanticsdoctoralthesis
keyword: mecanique-statistique-hors-equilibre
keyword: physphysphys-flu-dynphysics-physicsphysics-physicsfluid-dynamics-physicsflu-dyn
keyword: superfluidite
keyword: theses
keyword: transitions-de-phase
keyword: turbulence
landing page: https://theses.hal.science/tel-00911544

The von Kármán flow as a paradigm for out-of-equilibrium statistical physics
type: Distribution
format: HTML
issued: 2026-05-08T00:49:22.567080
modified: 2026-05-08T00:49:22.541344
access URL: https://theses.hal.science/tel-00911544

test_moissonnage_selune
type: Agent