ANALYSIS OF A SHORT SQUEEZE-FILM DAMPER OPERATING WITH ELECTRORHEOLOGICAL FLUIDS

This paper addresses the lubrication analysis of a short squeeze-film damper operating with electrorheological (ER) fluids which have large and reversible changes in yield shear stresses with respect to an applied electric field. The ER fluids are assumed to be modeled as Bingham fluids. The governing lubrication equation for the ER short squeeze-film damper is developed an the basis of a Bingham fluid model, and the equation is subsequently solved in order to investigate the effects of the ER fluids on the damping capability of the damper It is shown that a substantial increase in both direct and cross-coupled damping is accomplished by increasing the yield shear stress of the ER fluids. This significant improvement of the damping capability suggests that the ER short squeeze-film damper could be very effective for reducing the vibration and controlling the critical speeds of a rotor system.