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Accueil du site > Séminaires > Archives séminaires > Séminaires 2012 > Séminaire MSC lundi 18 juin 2012 à 11h30. Rob Poole (Univ. Liverpool, UK) - Purely-elastic flow instabilities of viscoleastic liquids.

MSC Seminar, Monday June 18th, 2012. Rob Poole (Univ. Liverpool, UK) - Purely-elastic flow instabilities of viscoleastic liquids

Unless otherwise stated, seminars and defences take place at 11:30 in room 454A of Condorcet building.

Attention lieu exceptionnel

Amphithéâtre Pierre-Gilles de Gennes du Bâtiment Condorcet (niveau -1).

Rob Poole, University of Liverpool

PNG - 58.7 kb

The flow of viscoelastic fluids, e.g. polymer solutions or melts, can often give rise to spectacularly different flow phenomena compared to "simple" Newtonian fluids (water or air). One such manifestation of these differences is that in microfluidic geometries viscoelastic fluid flows can become unstable and time dependent in simple geometries at flow rates much smaller than would arise in the equivalent flow of a Newtonian fluid (typically due to inertial instabilities). Such "purely-elastic" flow instabilities arise as the inherently small scale of microfluidic flows accentuates the viscoelastic behaviour observed: the small length scale simultaneously makes the Reynolds number small and the Deborah or Weissenberg numbers, which characterize the degree of elasticity in the flow, large. In this talk I will discuss how we have been able to model one such experimentally-observed instability in a cross slot geometry. I will then go on to briefly examine a series of purely-elastic instabilities that we have discovered in related geometries and some recent experimental verification of one such truly a priori prediction.

Contact : Équipe séminaires / Seminar team - Published on / Publié le 21 March 2012

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