SHEAR-FLOW INDUCED DEFORMATIONS OF PLANAR CHOLESTERIC LAYERS

The shear flow induced deformation of the planar cholesteric structure is modelled numerically, taking into account long pitch flow-aligning material. Three pitch-to-thickness ratios in five configurations are considered. Unwinding of the cholesteric helix due to the flow alignme nt is found. This process has a threshold character, when the mid-plan e director is perpendicular to the plane of shear; otherwise it is con tinuous. The transverse component of the flow is always present. At hi gh stress, the director in the prevailing part of the layer is oriente d at the flow-aligning angle.