18 novembre 2021

Webinar Bjorn Hof

B. Hof obtained his PhD in 2001 from University of Manchester, UK. From 2003 to 2005 he was Research Associate at Delft University of Technology, The Netherlands and from 2005 to 2007, lecturer at University of Manchester. From 2007 to 2013 B. Hof was the leader of a research group at Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany. Since 2007, he is Professor at the Institut of Science and Technology (IST) Austria.
Elasto-inertial turbulence

Abstract: In pipe and channel flows turbulence generally arises if velocities and hence inertial forces are sufficiently large. In striking contrast, viscoelastic fluids can exhibit disordered motion even at vanishing inertia. Intermediate between these cases, a novel state of chaotic motion, ‘elasto-inertial turbulence’ (EIT), has been observed in a narrow Reynolds number interval. I will here discuss the relation between EIT and polymer drag reduction, in particular its relation to the so called ‘maximum drag reduction asymptote’ at high Reynolds numbers. I will moreover show that in experiments the onset of EIT can be traced to Reynolds numbers of order one. In this limit the flow structures closely resemble those predicted by a recently discovered linear instability for viscoelastic fluids.

18 novembre 2021, 16h3017h30
Please contact F. Romano for the link