Flows Excited by Shear Stress in Freestanding Symmetric Smectic C Films

Abstract

The purpose of this paper is to show some useful routes in describing the shear-driving flows in a freely suspended symmetric smectic C film stretched between two circular frames, the rest outer and rotating inner frames. Our calculations, based on a corresponding extension of the Eriksen–Leslie theory, show that the shear-driving flow in the film, excited by a rotating inner circular frame, causes a twisting rotation of the c^-director around the normal to smectic layers. It is found that the shear flow excited by the rotating frame in a positive sense (counterclockwise) causes a twisting rotation of the c^-director in a negative sense (clockwise) around the normal to smectic film. It is also shown that the twisting of the c^-director’s field has a jumping nature when a large reorientation is carried out in a short space of time. It was also shown that the twisting dynamics of the c^-director field strongly depends on the curvature of the inner rotating frame.