Couette flow of electrorheological fluids between two concentric cylinders with wall slip

The Couette flow of electrorheological (ER) fluids between two concentric cylinders with wall slip is considered in the present paper. ER fluids can be closely approximated as Bingham plastics. Based on the Navier slip model in the wall boundaries, the characteristics of slip flow, in particular the effects of velocity slip on the location of yield surface, are obtained by an analytical method. It is shown that the wall slip has a great effect on the velocity distribution and the location of the yield surface. In the scope of the slip coefficient discussed, the wall slip velocity increases first with increasing slip coefficient; after reaching a maximum, the slip velocity then decreases on further increase of the slip coefficient. The moments exerted by ER fluids on the walls decrease as the slip coefficient increases.