Influence of an Orienting Field on the Viscosity of a Molecular Liquid

Abstract

From phenomenological consideration follows that both the field-induced anisotropy of the shear viscosity and the effect reciprocal to the flow birefringence contribute to the anisotropy of the effective viscosity in a Couette or a Poiseuille geometry, as well as to transverse effects and normal pressure differences. A Fokker-Planck equation approach links these mechanisms and yields a relation between two viscosity coefficients associated with the molecular orientation.