Study of factors influencing the wall slip of a magnetorheological fluid

The wall slip of magnetorheological (MR) fluids refers to a phenomenon that affects the application of mechanical properties of magnetorheological fluids due to the relative slippage between the magnetic particles and the transmission wall. In this paper, we analyze and experimentally verify the factors affecting the wall slip of magnetorheological fluids, which can limit the application of magnetorheological-fluid devices. Firstly, from the theoretical point of view, it is considered that the influencing factors are mainly divided into two parts: magnetorheological fluid's own parameters and transmission surface roughness, among which the parameters include viscosity, mass fraction, etc. When studying the influence of the transmission surface roughness, it is found that different surface morphologies have a great influence on the shear stress. Secondly, a magnetic field simulation analysis and shear yield stress experiments are conducted on shear blocks with different surface morphologies; the obtained results are compared and verified, confirming that different surface shapes affect the shear yield stress by changing the magnetic field distribution of the groove, which in turn changes the wall slip characteristics. These findings provide an effective basis for further research on the wall slip of magnetorheological fluids to improve the transmission effect.