FE analysis of electromagnetic field coupled with fluid dynamics in an MR clutch

Purpose - The aim of this paper is to find an accurate model for the finite element analysis of coupled phenomena in the dynamic operation of a magnetorheological clutch (MR CLUTCH). Design/methodology/approach - The rheological properties of magnetorheological fluid (MRF) depend on magnetic field distribution. Therefore, the field-circuit model of electromagnetic phenomena is coupled with the fluid motion model of MRF. The finite element method and time stepping algorithm are used to solve the examined problem. The eddy currents in massive conducting elements are taken into consideration. In order to include the nonlinearity of ferromagnetic core and non-linear theological properties of MRF, the Newton procedure is applied. This procedure is joined with the block-over relaxation algorithm in order to reduce calculation time. Findings - The proposed method gives sufficient accuracy of coupled electromagnetic and magnetorheological phenomena analysis. The comparison between measured and calculated clutching torque values shows a good agreement. Research limitations/implications - Thermal and hysteresis effects are not taken into account. Originality/value - The presented approach can be useful for designing and optimizing NW devices with axial symmetry. The accurate finite-element model of coupled electromagnetic and mechanical phenomena is used as a tool for the analysis of MR device dynamic operation.