TITLE:
Numerical Simulation of Liquid Crystal Flow Induced by Annihilation of a Pair of Defects
AUTHORS:
Shigeomi Chono, Tomohiro Tsuji
KEYWORDS:
Complex Fluid, Liquid Crystal, Defect, Annihilation, Generation of Flow
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.8 No.4,
November
6,
2018
ABSTRACT: We investigate the flow induced by annihilation of a pair of defects in liquid
crystals using the Doi theory with the Marrucci-Greco potential, in which the
orientation state is described with the orientational distribution function. We
have numerically studied both the transient behaviors of two defects with
different structures and their velocity field, and estimated the magnitude of
the induced velocity. A defect with positive strength moves faster than one
with negative strength. The long-range order of the molecular orientation
field has a large effect on the annihilation time, and the annihilation time is
reduced by increasing the long-range order. We find that flows are induced
during the annihilation of a pair of defects and that several vortices are generated
in the vicinity of the defects. The maximum velocity is predicted to
develop spatially between the two defects just after their annihilation in time.
In our simulation, the maximum induced velocity reaches an order of 10
μm/s. The induced velocity increases with increasing long range-order and
nematic potential strength.