NUMERICAL STUDY OF THE RESPONSE-TIME OF ER SUSPENSIONS

Transient response of model ER suspensions to step-wise electric field under steady shear flow is studied by numerical simulations. The elec trically induced stress increases almost linearly with time up to the steady-state value, and this increase directly reflects the growth of the chain-like clusters of the dispersed particles. As the shear rate increases, the response becomes faster since the growth rate of the cl usters increases and the steady-state length of the clusters decreases . The response also becomes faster by increasing the particle density or electric field, but the dependence on the field strength is rather weak.