Stable multi-layer flows at all Re. Viscoplastic lubrication of shear-thinning and viscoelastic fluids.
by
Miguel Moyers-Gonzalez
University of Canterbury
Coauthors: Ian Frigaard and Cherif Nouar.

In this work we study multi-layer flows that are linearly stable even at infinite Reynolds number. First we eliminate interfacial instabilities by ensuring that for the base flow configurations studied we maintain an unyielded plug region at the interface by using a yield stress fluid (for simplicity a Bingham fluid) as a lubricant. Secondly we eliminate linear shear instabilities by ensuring a strong enough Couette component in the lubricated fluid layer. The lubricated fluids that we consider are either a Carreau fluid (shear-thinning) or a modified Chilcott-Rallison FENE fluid (MCR fluid, viscoelastic).

Date received: January 10, 2010