In order to make sure a healthy servicing of a real MR damper in lifetime long, a mechanism called sedimentation-immunity was proposed featuring with active dispersion of settled MR fluid, which recovers the MR fluid to uniform before the adverse effect brought to the MR damper.
Circulating channel is required for a sedimentation-immunized MR damper and which cannot be provided with single tube MR dampers, consequently, twin-tube structure is employed and the inner tube is holed in two ends to form the circulating channel between the tubes when the MR fluid is propelled.
In this paper, a FEM model is established to reveal the redispersion process once the MR fluid settled to a specific degree, and the optimal propulsion parameters for settled MR fluid are given out by the simulation. A method for local concentration sensing of MR fluid based on small wire wound inductors is employed to verify the re-dispersing process of MR fluid in experiments.
Ultimately, a self-adaptive system which could be able to judge whether MR fluid meets the normal working requirements of MRDs, and propel settled MR fluid through the circulating channels into uniform distribution, that arises out of enormous significance for prolonging the life of MRDs, was obtained.
 

Active dispersing,MR damper,concentration sensing,Sedimentation-immunity