Abstract
The effect of periodic AC and pulse electric fields on the shear stress of an Electrorheological Fluid is investigated by computer simulations. It is observed that as the frequency of the applied field (ω) is increased under a constant rate of shear (_??_), the shear stress passes through a minimum. It is found that there is a distinct difference in the aggregation processes due to the induced electric dipoles at frequencies above and below this critical frequency; for low frequencies the clustering follows the electric field variation, while at high frequencies the clusters are unable to completely break up. These considerations of the clustering process lead us to propose a scaling law for the shear stress: σxy=σxy(ω/_??_). This result agrees with experiments and with computer simulations.
