Development and Testing of Hybrid Magnetic Responsive Fluid for Vibration Damper

Abstract

A new intelligent fluid is studied and developed. Rheological characteristics of the developed fluid change rapidly and can be controlled in the presence of an applied magnetic field. The developed fluid is a hybrid type fluid, and it consists consisting of carbonyl irons and super fine magnetite. Average diameters of carbonyl iron and super fine magnetite are a size in the order of a few microns and about 10 nano-meters respectively. Special treatment is made by coating the surface of carbonyl iron with super fine magnetite. Physical properties such as dispersion stability and thixotropical characteristics are examined. Shearing stress and pressure drops of the new fluid flow are examined and evaluated by changing the strength of magnetic fields. A small capacity damper is made, and damping tests are performed using the new fluids and also commercial MR fluid. Dynamic properties of the damper are evaluated. As a result of a series of studies, the developed hybrid magnetic responsive fluid is expected to be used as an intelligent fluid.

Magnetic levitation force of composite magnets in a ferrofluid damper

“…Such unique characteristic makes it possible to be used as supporting and damping elements in dampers [3,4] and other separation applications [5]. Until now, several types of ferrofluid dampers have been proposed and investigated [6], including the piston type dampers [7,8], active ferrofluid dampers [9], brakes [10], shock absorbers [11,12], tuned liquid dampers [13,14], smart colloidal dampers [15], porous elastic sheet dampers [16] and the simple ferrofluid dampers [3,17,18]. In several of these ferrofluid dampers, permanent magnets as the moving parts are suspended relying on magnetic levitation force exerted on them immersed in ferrofluid.…”