EVENT DETAILS AND ABSTRACT

Title: Electroconvection patterns in suspended smectic films
Speaker: Professor Steve Morris
Speaker Info: U. Toronto, Canada
Brief Description:
Special Note: unusal day and time
Abstract:

Suspended films of smectic liquid crystals behave as nearly ideal 2D fluids, and can be made to flow very rapidly without thickness variation. They therefore make good working fluids for the study of simple fluid-mechanical instabilities. We report on experiments and theory on electrically driven convection in such films. Convection is caused by an unstable surface charge distribution which develops on the two free surfaces of the film. Using an annular film holder, we have studied the effect of superimposing an azimuthal shear flow on radially driven convection. Without shear, the flow pattern above onset consists of symmetric vortices. Under shear, the vortices travel and become asymmetric. The onset of convection becomes hysteretic above a critical value of the shear strength. For more information and references, see http://mobydick.physics.utoronto.ca