Complex dynamics of shear banded flows
- Event time: 1:00pm
- Event date: 26th March 2007
- Speaker: Suzanne Fielding (University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Complex fluids commonly undergo flow instabilities and flow-induced transitions that result in spatially heterogeneous ''shear banded'' states. Often, these banded states display oscillatory or chaotic dynamics, measured in the bulk rheological signals and in the motion of the interface between the bands. Until recently, however, theory predicted a steady state comprising stationary bands separated by a flat interface. We discuss recent theoretical progress in capturing complex dynamics of the banded state: first in a model in which the interface (or interfaces) remains flat but moves in a chaotic way; second in a model that explicitly allows for undulations along the interface. Time permitting, we will also discuss the formation of vorticity structuring, as a secondary instability to ordinary shear bands.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..