Electrorheological Effect of Reducing the Suspension Viscosity in Laminar Flows below the Viscosity of Anisotropic Dispersive Medium

Abstract

Electrorheological features of a dilute suspension in Ericksen anisotropic fluid are analyzed on the basis of rheological constitutive equations obtained in the present paper. It is assumed that suspended particles possess a zero bouyancy and constant dipole moment, the anisotropic dispersive medium of suspension is electrically neutral. As a hydrodynamic model of suspended particles, the uniaxial dumbbell is used. The sizes of suspended particles are assumed to be much more than elements of microstructure which are responsible for anisotropy of dispersive medium. The rheological equations of suspension under consideration are obtained on the basis of the structure-phenomenological approach. The rheological behavior is suspension is investigated in a simple shear flow in the presence of external electric field. It is shown that the suspension behaves itself as anisotropic non-Newtonian fluid. The possibility of reducing the effective viscosity of suspension of laminar shear flows below the value of effective viscosity of anisotropic dispersive medium is predicted theoretically. It takes place at certain orientation of suspension particles of suspension under action of the external stationary electric field and the hydrodynamic forces. The result obtained can be used for studying the suspension in liquid crystals.