This project will focus on numerical investigations
of continuum models of nematic and smectic C materials using
calculated material properties and surface anchoring potentials
from Projects 1, 2, 6, 8 and 9. The properties of the model
will be investigated using the numerical bifurcation technique
ENTWIFE which permits the calculation of critical points
and their dependence on control parameters. It is able to
handle physical boundary conditions on length scales which
are appropriate for both large scale and pixel size devices.
We have already calculated microscopic flows in nematics
and compared the results with those obtained from complimentary
experimental investigations of electrohydrodynamic connection
in nematics [1]. In
addition we have calculated bifurcation phenomena associated
with Freedericksz transitions [2]
in nematics and included the effects of physical imperfections
which will be present in any device
.
More recently we have extended the technique to investigation
transient behaviour at transitions [3]
and uncovered novel scaling properties. This approach will
be extended and applied to switching transitions in smectic
C materials to consider the importance of both layer motion
and flow within the layers during device manufacture and
operation. The guided mode techniques developed by Prof.
Sambles will provide the experimental data with which to
fit optical calculations of the director configurations.
Full device simulation and optimisation can then be carried
out, and this will be used to guide experimental device
testing thereby reducing the time and cost of these necessary
practical procedures.
[1]S J Tavener, T Mullin, G I Blake
and K A Cliffe 2001 'A numerical investigation of electrohydrodynamic
convection' Phys Rev E
6301, 1708-20.
[2]
G I Blake, T Mullin and S J Tavener 1999 'The Freedericksz
transition as a bifurcation problem' Dynamics
and Stability of Systems 14, 299-331.
[3]
J Abshagen, O Meincke, G Pfister, K A Cliffe and T Mullin
2003, 'Nonlinear response to the onset of Taylor cells'
J Fluid Mech 476, 335-43.
