European Turbulence Conference 2015

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10:45
15 mins

EFFECT OF VISCOELASTICITY ON THE FAR-DISSIPATION RANGE OF HOMOGENEOUS ISOTROPIC TURBULENCE
Minh Quan NGUYEN, Serge Simöens, Alexandre Delache, Mahmoud El Hajem, Wouter Bos, Robert Poole

Session: Multiphase and non-Newtonian flows 4
Session starts: Friday 28 August, 10:30
Presentation starts: 10:45
Room: Room D

Minh Quan NGUYEN (LMFA UMR 5509 CNRS, Ecole Centrale de Lyon, Université de Lyon, France)
Serge Simöens (LMFA UMR 5509 CNRS, Ecole Centrale de Lyon, Université de Lyon, France)
Alexandre Delache (LMFA, site de Saint-Etienne, Université de Lyon, Université Jean Monnet de Saint-Etienne, France)
Mahmoud El Hajem (LMFA UMR 5509 CNRS, INSA de Lyon, Université de Lyon, France)
Wouter Bos (LMFA UMR 5509 CNRS, Ecole Centrale de Lyon, Université de Lyon, France)
Robert Poole (School of Engineering, University of Liverpool, United Kingdom)

Abstract:
The comparison of the results of direct numerical simulations of isotropic turbulence of Newtonian and viscoelastic fluid, based on the FENE-P model, provide evidence that viscoelasticity modifies qualitatively the behavior of the smallest scales: we observe a k−6 law in the far dissipation range of the energy spectrum and we show that it is a robust feature, roughly independent of the large-scale dynamics. It is further shown that the drag-reduction in such flows, as measured by the difference in energy dissipation between Newtonian and viscoelastic flow, strongly depends on the initial conditions.