Behavior of a nematic liquid crystal in oscillatory flow at weak surface anchoring

The effect of the surface viscosity on the orientational dynamics of a nema tic liquid crystal in an oscillatory flow has been studied. For the shear a nd the Poiseuille fews, the approximate analytical solutions of the nematod ynamic equations are obtained at small flow amplitudes. The frequency range of the oscillatory flow is determined, in which the surface viscosity stro ngly affects the optical response of a nematic layer. The results obtained are compared with the data of direct numerical simulation of the nematodyna mic equations and the method for the experimental determination of surface viscosity is proposed. (C) 2001 MAIK "Nauka/Interperiodica".