Scaling temperature dependent rheology of magnetorheological fluids

Abstract

Articles you may be interested inRheological characterization of a magnetorheological ferrofluid using iron nitride nanoparticles Magnetorheological behavior of magnetite covered clay particles in aqueous suspensions J. Appl. Phys. 112, 043917 (2012); 10.1063/1.4748878Magnetorheology and sedimentation behavior of an aqueous suspension of surface modified carbonyl iron particles Magnetorheological (MR) fluids are suspensions of micron-scale magnetizable particles suspended in a carrier fluid. When field is applied, MR fluids develop a field controllable yield stress and a field independent post-yield viscosity. However, this viscosity has substantial temperature dependence, varying by up to an order of magnitude over the operating temperature range of MR fluid devices. We apply non-Brownian suspension theory to explain this result and find that the majority of this effect should be caused by the temperature dependent behavior of the carrier fluid. Thus, if two fluids share the same carrier fluid, then their fluid properties should scale in temperature similarly. This result is first validated by measuring viscosity across temperature for custom model fluids designed to conform to theory, showing temperature scaling within 5% for both the MR fluids and their carrier fluid. Then, on a series of related commercially available fluids with unknown additive content, we show that the MR fluids exhibit common scaling to within 4%. We also investigate the effects of magnetic hysteresis and find that it induces a negligible increase in yield stress and no measurable change in viscosity. We conclude that our non-dimensional analysis enables the temperature dependence of novel MR fluids to be characterized with fewer experiments. V C 2015 AIP Publishing LLC. [http://dx.

Magnetorheology: a review

“…In particular, both thermal and electric conductivities increase when the MRF is magnetized in the field direction. Some recent examples on thermal studies are as follows: Ocalan and McKinley, 148 Yildirim and Genç, 169 Sherman et al 170 and Patel and Upadhyay. 171 Very recently, Ruan et al 172 investigated the influence of oscillatory shear on the magnetic field dependent electric conductivity of MRFs.…”

Temperature Estimation in a Magneto–Rheological Damper

“…4 the opposite happens. Hence, the only plausible conclusion is the relationship between current and voltage, in our scenario, is not constant as in (2). Therefore, given any constant value for the current amplitude (different from zero), the relationship between MR fluid's temperature and coil's resistance is well defined.…”

“…It is well known in literature that the viscosity of the MR fluid is significantly affected by the operating temperature [2], [3], [4] diminishing the damping capabilities of the MR damper [5], [6]. As remarked in [7], since the MR damper dissipates the vehicle mechanical energy, the heating of the internal damper fluid cannot be avoided.…”

Performance and Stability of Magnetorheological Fluids—A Detailed Review of the State of the Art

“…The authors attribute the difference in behavior to the viscosity decrease of the carrier fluid dominating in the absence of magnetic field, whereas magnetic attraction between iron particles is dominant in the presence of magnetic field. Computational work by Sherman et al [ 67 ] similarly showed that temperature behavior is dependent on the carrier fluid for CI‐based polyalphaolephin (PAO) hydrocarbon oil MRFs. Wu et al [ 68 ] investigated the effect of particle size and concentration in addition to temperature on τ y and magnetization.…”