A lattice Boltzmann scheme is presented which recovers the dynamics ofnematic and chiral liquid crystals; the method essentially gives solutions tothe Qian-Sheng equations for the evolution of the velocity and tensororder-parameter fields. The resulting algorithm is able to include fiveindependent Leslie viscosities, a Landau-deGennes free energy which introducesthree or more elastic constants, a temperature dependent order parameter,surface anchoring and viscosity coefficients, flexo-electric and orderelectricity and chirality. When combined with a solver for the Maxwellequations associated with the electric field, the algorithm is able to providea full 'device solver' for a liquid crystal display. Coupled lattice Boltzmannschemes are used to capture the evolution of the fast momentum and slowdirector motions in a computationally efficient way. The method is shown togive results in close agreement with analytical results for a number ofvalidating examples. The use of the method is illustrated through thesimulation of the motion of defects in a zenithal bistable liquid crystaldevice.
展开▼
