title: Vortex flow in freestanding smectic films driven by elastic relaxation of the c director.
abstract: We report a simple experiment in freestanding smectic films in which elastic distortions of the c director drive macroscopic flow. The flow field is visualized with tracer particles. Measurements are compared to predictions of a model that employs the coupled dynamic equations for director and velocity fields. Relaxation dynamics depends on the topology of the film center: for defect-free target patterns, shear flow provides the dominating contribution to the c director dynamics. In presence of a central topological defect of strength S = + 1, the influence of flow on the relaxation dynamics is practically negligible, while for a central S = - 1 defect, the influence of vortex flow on the c-director relaxation is roughly twice as large as for the defect-free state.
authors.affiliation: Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Stannarius
authors.forename: Christian
authors.initials: C
authors.lastname: Bohley
authors.forename: Alexey
authors.initials: A
authors.lastname: Eremin
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D004548:Elasticity; D004574:Electromagnetic Fields; D050866:Liquid Crystals / Q000737:chemistry*