Continuum Theory of Cholesteric Liquid Crystals

This paper discusses a continuum theory which has recently been proposed for liquid crystals of the cholesteric type. As in earlier continuum theories, the liquid crystal is regarded as an incompressible liquid with a preferred direction at each point, described by a unit vector. Solutions of the equations are investigated for shear flow between two flat plates, one at rest, and the second moving parallel to the first with a constant velocity. It is found that the theory predicts non-Newtonian behaviour, and that secondary flow and temperature variations occur. The predictions are compared with available experimental data, and one finds agreement in that a uniform apparent viscosity is predicted at large shear rates.