Title
Energy Minimization for Liquid Crystal Equilibrium with Electric and Flexoelectric Effects.
Abstract
This paper outlines an energy-minimization finite-element approach to the modeling of equilibrium configurations for nematic liquid crystals in the presence of internal and external electric fields. The method targets minimization of free energy based on the electrically and flexoelectrically augmented Frank-Oseen free energy models. The Hessian, resulting from the linearization of the first-order optimality conditions, is shown to be invertible for both models when discretized by a mixed finite-element method under certain assumptions. This implies that the intermediate discrete linearizations are well-posed. A coupled multigrid solver with Vanka-type relaxation is proposed and numerically vetted for approximation of the solution to the linear systems arising in the linearizations. Two electric model numerical experiments are performed with the proposed multigrid solver. The first compares the algorithm's solution of a classical Freedericksz transition problem to the known analytical solution and demonstrates the convergence of the algorithm to the true solution. The second experiment targets a problem with more complicated boundary conditions, simulating a nano-patterned surface. In addition, numerical simulations incorporating these nano-patterned boundaries for the flexoelectric model verify expected physical behavior predicted by a perturbation model. The algorithm accurately handles heterogeneous coefficients and efficiently resolves configurations resulting from classical and complicated boundary conditions relevant in ongoing research.
Year
DOI
Venue
2015
10.1137/140975036
SIAM JOURNAL ON SCIENTIFIC COMPUTING
Keywords
Field
DocType
nematic liquid crystals,mixed finite elements,saddle-point problem,Newton linearization,energy optimization,coupled multigrid,Vanka relaxation
Discretization,Mathematical optimization,Linear system,Mathematical analysis,Hessian matrix,Solver,Liquid crystal,Multigrid method,Mathematics,Linearization,Energy minimization
Journal
Volume
Issue
ISSN
37
5
1064-8275
Citations 
PageRank 
References 
3
0.44
6
Authors
5
Name
Order
Citations
PageRank
J. H. Adler15610.02
T. J. Atherton2133.10
Thomas R. Benson381.29
D. B. Emerson4112.00
S. P. MacLachlan59811.78