title: Flow enhancement due to elastic turbulence in channel flows of shear thinning fluids.
abstract: We explore the flow of highly shear thinning polymer solutions in straight geometry. The strong variations of the normal forces close to the wall give rise to an elastic instability. We evidence a periodic motion close the onset of the instability, which then evolves towards a turbulentlike flow at higher flow rates. Strikingly, we point out that this instability induces genuine drag reduction due to the homogenization of the viscosity profile by the turbulent flow.
authors: Université de Bordeaux, CNRS, Solvay, LOF UMR 5258, Pessac 33600, France.
authors: Hugues
authors: H
authors: Bodiguel
authors: Université de Bordeaux, CNRS, Solvay, LOF UMR 5258, Pessac 33600, France.
authors: Julien
authors: J
authors: Beaumont
authors: Université de Bordeaux, CNRS, Solvay, LOF UMR 5258, Pessac 33600, France.
authors: Anaïs
authors: A
authors: Machado
authors: Université de Bordeaux, CNRS, Solvay, LOF UMR 5258, Pessac 33600, France.
authors: Laetitia
authors: L
authors: Martinie
authors: Université de Bordeaux, CNRS, LOMA UMR 5586, Talence 33501, France.
authors: Hamid
authors: H
authors: Kellay
authors: Université de Bordeaux, CNRS, Solvay, LOF UMR 5258, Pessac 33600, France and Université de Bordeaux, CRPP, UPR 8641, Pessac 33600, France.
authors: Annie
authors: A
authors: Colin