A quasi-static model for the pinch mode analysis of a magnetorheological fluid flow with an experimental validation

Abstract

Abstract The flow behaviors of a magnetorheological fluid (MR fluid) can be divided into four operating modes: flow, shear, squeeze and pinch mode. Despite many research works on the first three modes, the study on the pinch mode is relatively few. This study proposes a new mathematical model of the pinch mode flow motion of MR fluid and its fidelity is verified through a comparison with experimental results. In order to achieve this goal, the flow configuration of the pinch mode is provided followed by the magnetic analysis to design an appropriate magnetic circuit and to obtain the relationship between the magnetic intensity and applied current. Then, a mathematical model for predicting the pinch mode flow motion is formulated based on the quasi-static flow associated with several different conditions of the flow velocity. It is shown from a comparative work between the simulation results from the proposed mathematical model and experimental test results of the pinch mode MR damper that the proposed model fairly well predicts the field-dependent damping force in a low flow volume domain.