Author(s)

K. von Pfeil, M.D. Graham, D.J. Klingenberg & J.F. Morris

Abstract

One-dimensional analysis of a continuum model for structure in electrorheological fluids K. von ~ f e i l ' , M.D. ~raham', D.J. IClingenbergl & J.F. Morris2 1 Department of Chemical Engineering, University of Wisconsin, USA 2 Halliburton Energy Services, USA Abstract A continuum model is used to describe the evolution of nonuniform particle concentration distributions in electrorheological and magnetorheological fluids. Particles are shown to migrate relative to the bulk mixture motion as the result of the particle-phase contribution to the suspension stress. The particle stress results from both electrostatic and hydrodynamic contributions; the ratio of hydrodynamic to electrostatic stress is characterized by the Mason number, Mn. The model predicts structures which are in agreement with those observed experimentally for both unsheared and sheared conditions. The emphasis here is on the sheared condition, where particle-rich stripes with normal along the vorticity direction of a simple shear

Keywords