Identification of an ER Fluid in Unsteady Flow with Random Electric Field and Solidification

An identification procedure to simultaneously determine electrorheological (ER) and viscous characteristics of an ER fluid is presented. The analysis is performed under unsteady flow conditions with randomly varying electric field and intermittent solidification of the fluid. Tests conducted using a standard viscometer and cylindrical couette geometry indicate that there is some interaction between viscous and ER effects and that some residual structuring persists in the fluid after removal of the electric field.