Properties of magnetorheologic fluids

A feasible model for efficiently describing the flow of magnetorheological fluids (MRF) in narrow channels, based on the Bingham equation, is presented. This model permits an accurate determination of shear stress tau, yield point tau sub f and Bingham viscosity eta sub B at high shear rates gamma exp * so far not investigated. These parameters are calculated from pressure difference Deltap and volume flow V exp * , measured under variable process conditions. Furthermore, the frequency characteristic of the relative permeability mu sub r of MRFs is investigated in the industrially significant range up to 1500 Hz.