Magnetorheological damper with multi-grooves on piston for damping force enhancement

Abstract Due to low power consumption and fast response, magnetorheological (MR) dampers are widely used in various engineering applications. To enhance the performances, efforts have been made to increase the field dependent force with the same power consumption. However, the fluid viscous force is also increased significantly, which is undesirable in practical use. To tackle this problem, the focus of this paper is to design, simulate, and test an MR damper with multi-grooves (small multiple annular flow gaps) on piston for performance enhancement. First, the detailed design of the proposed MR damper is provided. Then, a coupled field model to describe the characteristics of MR fluid in different regions of MR damper is derived. Based on this model, multiphysics simulations are performed using COMSOL Multiphysics. Parametric analysis of the number and width of multi-grooves is also conducted. Experimental results of the two MR dampers without and with multi-grooves are given and compared with the simulation results. The advantages of MR damper with multi-grooves over the one without multi-grooves and the accuracy of the coupled field model are validated by experiments and simulations. This is the first time that the advantages of MR damper with multi-grooves are validated by experiments. Compared with MR damper without multi-grooves, MR damper with multi-grooves has larger damping force and controllable force range, as well as less increment of fluid viscous force while keeping the same increase of field dependent force. The performance of MR damper with multi-grooves could be further improved by increasing the number and decreasing the width of multi-grooves.