Analysis of multiphysical field coupling and study of dynamic characteristics in magnetorheological fluid dampers

This paper presents multi-physical field coupling simulations of a magnetorheological fluid (MRF) damper equipped with bidirectionally adjustable permanent magnets under various operating conditions. The study analyzes the variation in flow velocity, pressure distribution, viscosity, and damping force of the MRF damper as influenced by different parameters using COMSOL software. A dynamic characteristics testing system was established to evaluate the mechanical properties of the MRF damper, and the accuracy of the simulated damping force was validated through experimental tests. The simulation results indicate that at different time points, the streamlines within the damping channel are straight and dense, while the streamline trajectories near the inlet and outlet of the damping channel exhibit greater complexity, and the streamlines are sparse around the piston rod and within the cavity. Additionally, the pressure distribution along the axial direction in the damping channel decreases with increasing axial distance. When the excitation current is increased from - 2.5 to 2 A, the damping force rises from 50 to 640 N, indicating a significant increase. The damping force also increases slightly with higher excitation frequency and amplitude, although the relative increase remains below 10%. The dynamic experimental results effectively validate the accuracy of the simulation calculations.