Dynamics of chevron structure formation

The natural structure for smectic-A liquid crystals arranged in a sample wi th homogeneous boundary conditions is the so-called bookshelf structure wit h uniform layers perpendicular to the sample cell plane. However, this stru cture often deforms into the so-called chevron structure when the sample is cooled. This deformation is usually thought to result from the mismatch be tween bulk and surface layer thicknesses. In this paper we study the dynami cs of chevron formation. Two possible scenarios are envisage. In one of the se there is strong coupling between layer deformation and fluid flow, and i n the other the fluid essentially does not move. In this paper we examine t he first scenario, leaving the second, slower relaxation mode for another p aper. Analytic solutions are found for near-critical deformations, and nume rical solutions are found beyond the critical regime. [S1063-651X(98)06912- 8].