Rheology of distorted nematic liquid crystals

Abstract

We use lattice Boltzmann simulations of the Beris--Edwards formulation of nematodynamics to probe the response of a nematic liquid crystal with conflicting anchoring at the boundaries under shear and Poiseuille flow. The geometry we focus on is that of the hybrid aligned nematic (HAN) cell, common in devices. In the nematic phase, backflow effects resulting from the elastic distortion in the director field render the velocity profile strongly non-Newtonian and asymmetric. As the transition to the isotropic phase is approached, these effects become progressively weaker. If the fluid is heated just above the transition point, however, another asymmetry appears, in the dynamics of shear band formation.