Micro-analysis of slip differential heat of magnetorheological fluids based on micromechanics and microstructures

Abstract

For describing the slip differential heat between two neighboring particles of magnetorheological fluids (MRFs) in shear and squeeze modes, a theoretical model was developed in this study based on micromechanics and microstructures. Firstly, the interaction force and the contact stress during the shear and squeeze deformation was analyzed based on the magnetic dipole theory and the Hertzian contact theory. And then the motion and the relative velocity of particles were analyzed by assuming the incline or bending of a single chain ordered in MRFs. Furthermore, the slip differential heat flow caused by the friction of neighboring particles in MRFs was analyzed based on the tribology theory. The model takes into account the effect of the main influencing factors on the slip differential heat flow between two neighboring particles in a single chain of MRFs in shear and squeeze modes, such as the magnetic induction intensity, the size of particles, the number of the particles in a single chain, the relative velocity between the upper and lower walls in shear mode and the squeeze velocity in squeeze mode. Using the proposed model, the individual effect of typical governing parameters on slip differential heat flow under the realistic conditions of the magnetorheological clutch and damper was investigated by the numerical simulation. The results indicate that these factors have great influences on the slip differential heat flow, and the proposed model can satisfactorily describe the main micro-characteristics of the slip differential heat of MRFs in shear and squeeze modes.