Coupled Magnetic and CFD Modelling of a Structural Magnetorheological Vibration Absorber with Experimental Validation

Abstract

Magnetorheological fluid is a smart material which can change its viscosity in milliseconds depending on the magnetic field applied. This brings a great advantage to create variable damping ability if it is used in an absorber. The stiffness of the absorber can be manipulated by an external magnetic field which effects the apparent viscosity of the magnetorheological fluid inside the absorber. Various control algorithms can be used to provide an effective absorption for any kind of structural vibration. Because of these features, magnetorheological absorbers have received great attention of researchers in the last decade. In this study, it is aimed to simulate a magnetorheological absorber under a sinusoidal vibration with Computational Fluid Dynamics and Magnetic Field Finite Elements Analysis. The magnetorheological fluid is modelled as a Non-Newtonian fluid and Herschel-Bulkley viscosity model is used to determine the apparent viscosity. Magnetic field is modelled for a constant current which generates different magnetic flux densities inside the absorber body. The Computational Fluid Dynamics and Finite Elements Analysis solutions are coupled in a two-dimensional axisymmetric domain and the results are revealed. The coupled solution of both are realized for the first time in the literature by means of an apparent viscosity approach. The numerical solution is compared with the experiments. A good agreement is observed between both results.