Investigating the characteristics of a magnetorheological fluid damper through CFD modeling

Abstract

Computational Fluid Dynamics (CFD) analysis is conducted on mono-tube vehicle MRF damper investigated experimentally in a previous study. In this study, the fluid of the type MRF-132DG was inserted inside a damper of a car rear suspension system. The CFD analysis describes the fluid flow through the internal orifices between the compression and the rebound chambers. Averaged Navier-Stokes equations were solved by the SIMPLE method, and the RNG k-ϵ was used to model the turbulence at the fluid crossing through the orifices. All the CFD model boundary conditions' values were set to the same values reported in the previous experimental study, except for the viscosity values. When varying the applied magnetic field density, the changes of MRF's viscosity values were assessed by using a viscosity meter. Results showed a viscosity increase of 70% when the magnetic field excitation current was elevated from 0 A to 5 A. The damping forced and damping values were calculated using the rebound and compression static pressures obtained from the contour plots. It was also observed that the damping values exponentially increase with the increase in viscosity. The results of the CFD simulation were compared against those from the experiments, and good matching was observed.