Greg Forest

The interplay between hydrodynamic feedback and defects in sheared nematic liquids

There is a rich history of defects in liquid crystals and liquid crystal polymers, which has focused almost exclusively on static morphologies, the topology of the nematic director field, followed by regularization by a blow-up of the core of the defect.  We show a tensorial or probability distribution description of a defect core provides accelerated detection and tracking strategies of defects, and applies more generally than topological defect metrics.  In the past decade or so, there has been a great deal of attention to shear banding in flows of anisotropic viscoelastic liquids such as wormlike micelles.  In this lecture we show strong correlations between dynamic defect morphology and strong flow feedback in benchmark non-equilibrium shear flows.
This lecture is based on joint work with several collaborators, especially the algorithms and simulations of X. Yang at North Carolina, recent projects with S. Heidenreich from the Hess group in Berlin and R. Zhou from Old Dominion University, and longstanding work with Q. Wang, now at U. South Carolina.