  We extend a lattice Boltzmann algorithm of liquid crystal hydrodynamics to
include an applied electric field. The approach solves the equations of motion
written in terms of a tensor order parameter. Back-flow effects and the
hydrodynamics of topological defects are included. We investigate some of the
dynamics relevant to liquid crystal devices; in particular defect-mediated
motion of domain walls relevant to the nucleation of states useful in pi-cells.
An anisotropy in the domain wall velocity is seen because defects of different
topology couple differently to the flow field.
