Viscosity of a one-component polarizable fluid.

Abstract

The viscosity of a one-component polarizable fluid in an electric field is studied by computer simulations. The fluid viscosity increases with the field through three stages. In a weak field, the fluid remains Newtonian, although its viscosity increases. At this stage, while drifting in the flow direction, particles diffuse in the direction perpendicular to the flow. In an intermediate electric field, the fluid has tilted and broken chains moving with the flow and the fluid becomes non-Newtonian. The viscosity \ensuremath{\eta} and the shear rate \ensuremath{\gamma}\ifmmode \dot{}\else \.{}\fi{} have the relationship \ensuremath{\eta}=${\mathrm{\ensuremath{\eta}}}_{0}$${\mathit{e}}^{\mathrm{\ensuremath{-}}\ensuremath{\gamma}\mathrm{\ifmmode \dot{}\else \.{}\fi{}}\mathrm{\ensuremath{\tau}}}$, where \ensuremath{\tau} is the relaxation time and ${\mathrm{\ensuremath{\eta}}}_{0}$ is exponentially proportional to the dipolar interaction energy and the volume fraction. In a strong electric field, the fluid contains condensed chains that provide yield stress and hysteresis.