Experimental study and CFD simulation of rotational eccentric cylinder in a magnetorheological fluid

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 13; pp. 2062 - 2069
• Main Authors: Omidbeygi, F., Hashemabadi, S.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2012; Elsevier
• Subjects: Carbonyl iron; CFD simulation validation; Computational fluid dynamics; Cross-disciplinary physics: materials science; rheology; Cylinders; Eccentricity; Eccentrics; Exact sciences and technology; Experimental study; Heterogeneous liquids: suspensions, dispersions, emulsions, pastes, slurries, foams, block copolymers, etc; Magnetic fields; Magnetorheological fluid; Magnetorheological fluids; Material form; Physics; Rheological property; Rheology; Rotational cylinder; Viscosity; Yield stress; Rheological property; CFD simulation validation; Experimental study; Rotational cylinder; Carbonyl iron; Magnetorheological fluid; Viscosity; Carbonyl compounds; Eccentricity; Computational fluid dynamics; Rheology; Magnetic field effects; Velocity distribution; Cylindrical shape; Iron compounds; Yield strength; Mathematical models
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.02.016

In this study, a magnetorheological (MR) fluid is prepared using carbonyl iron filings and low viscosity lubricating oil. The effects of magnetic field and weight percentage of particles on the viscosity of the MR fluid have been measured using a rotational viscometer. The yield stress under an applied magnetic field was also obtained experimentally. In the absence of an applied magnetic field, the MR fluid behaves as a Newtonian fluid. When the magnetic field is applied, the MR fluid behaves like Bingham plastics with a magnetic field dependent yield stress. Afterward, the results compared with those of CFD simulation of two eccentric cylinders in the MR fluid. Results show that the influences of MR effects, caused by the applied magnetic field, on the model characteristics are significant and not negligible. The viscosity is enhanced by increasing of the magnetic field, eccentricity ratio and weight percentage of suspensions. The MR effects and increasing of weight percentage and eccentricity ratio also provide an enhancement in the yield stresses and required total torque for rotation of inner cylinder. Also the simulation results indicate a good representation of the experiment by the model. ► Preparation of a magnetorheological fluid with carbonyl iron particles in lubricating oil. ► Rheological measurement for influence of solid content and magnetic field intensity. ► Simulation of eccentric rotating cylinder in prepared MR fluid with CFD techniques.