Dresden 2020 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 3: Fluid Physics of Turbulence
DY 3.4: Talk
Monday, March 16, 2020, 10:30–10:45, ZEU 118
Small scale structures of turbulence in terms of entropy and fluctuation theorems — Andre Fuchs1, •Joachim Peinke1, Matthias Waechter1, Silvio M. Duarte Queiros2, Alain Girard3, and Pedro G. Lind4 — 1Institute of Physics and ForWind, University of Oldenburg, — 2Centro Brasileiro de Pesquisas Fisicas and National Institute of Science and Technology for Complex Systems, Rio de Janeiro - RJ, Brazil — 3INAC-SBT, UMR CEA-Grenoble, 38054 Grenoble, France — 4Department of Computer Science, OsloMet - University, N-0130 Oslo, Norway
Experimental evidence that the integral fluctuation theorem as well as a detailed-like fluctuation theorem holds for large entropy values of the turbulent cascade processes. Stochastic equations describing the scale-dependent cascade process are derived. From individual cascade trajectories an entropy term can be determined. Since the statistical fluctuation theorems set the occurrence of positive and negative entropy events in strict relation, we are able to verify how cascade trajectories, defined by entropy-consumption or entropy-production are linked to turbulent structures: Where as trajectories with entropy-production show expected decreasing behavior; trajectories with entropy-consumption end at small scale velocity increments with finite size and show a lower bound for small scale increments. This indicates a tendency to local discontinuities in the velocity field.