Enhanced dispersion by elastic turbulence in porous media
1 2. Physikalisches Institut, Universität Stuttgart - Pfaffenwaldring 57, 70569 Stuttgart, Germany
2 Max-Planck-Institut für Intelligente Systeme - Heisenbergstraße 3, 70569 Stuttgart, Germany
Received: 17 June 2014
Accepted: 11 August 2014
We experimentally investigate hydrodynamic dispersion in elastic turbulent flows of a semi-dilute aqueous polymer solution within a periodic porous structure at ultra-low Reynolds numbers by particle tracking velocimetry. Our results indicate that elastic turbulence can be characterized by an effective dispersion coefficient which exceeds that of Newtonian liquids by several orders of magnitude and grows non-linearly with the Weissenberg number Wi. Contrary to laminar flow conditions, the velocity field, and thus the shear rate, is not proportional to the flow rate and becomes asymmetric at high Wi.
PACS: 47.56.+r – Flows through porous media / 47.50.-d – Non-Newtonian fluid flows / 47.50.Gj – Instabilities
© EPLA, 2014