Publications Details
Thermal chain model of electrorheology and magnetorheology
Steady shear simulations of electrorheology (ER) and magnetorheology (MR) in a uniaxiai field are presented. These large scale simulations are three dimensional, and include the effect of Brownian motion. In the absence of thermal fluctuations, the expected shear thinning viscosity is observed and a striped phase is seen to rapidly form in a uniaxiai field, with a shear slip zone in each sheet. However, as the influence of Brownian motion increases, the fiuid stress decreases, especially at lower Mason numbers, and the striped phase eventually disappears, even when the fluid stress is still high. To account for the uniaxiai steady shear data we propose a microscopic chain model of the role played by thermal fluctuations on the rheology of ER and MR fluids that delineates the regimes where an applied field can impact the fluid viscosity, and gives an analytical prediction for the thermal affect. ©2000 The American Physical Society.