Dissipative particle dynamics simulation of magnetorheological fluids in shear flow

Abstract

In the present study, the behavior of a magnetorheological fluid (MRF) in shear flow is investigated using dissipative particle dynamics (DPD), a particle-based method. The solid particles in the MRF are modeled by a magnetization model, and Lennard-Jones potential is used to simulate the interaction between the solid and the liquid phases. The columnar structure (chain) of the solid particles along the applied magnetic field direction is modeled that is similar to previous experimental observations. Subsequently, this complex fluid is simulated under shear flow and the velocity profiles depict the “plug region”. The effect of shear rate and area fraction on the rheological properties is investigated by Irving–Kirkwood model. The DPD simulation results indicate a shear-thinning and viscoplastic behavior of MRF which is similar to experimental reports. Following, the effect of magnetization of solid particles is also studied and it is shown that the MR effect is significantly dependent to the solid particle magnetism. Furthermore, the results show that the viscosity of base fluid has a considerable effect on the dynamic range of this smart fluid.