1 research outputs found
Controlling colloidal sedimentation using time dependent shear
Employing a recently developed dynamical density functional theory we study
the response of a colloidal sediment above a wall to shear, demonstrating the
time dependent changes of the density distribution and its center-of-mass after
switching shear either on or off and under oscillatory shear. Following the
onset of steady shear we identify two dynamical mechanisms, distinguished by
their timescales. Shortly after the onset, a transient enhancement of the
packing structure at the wall reflects the self-organization into lanes. On a
much longer timescale these effects are transmitted to the bulk, leading to
migration away from the wall and an increase in the center-of-mass. Under
oscillatory shear flow the center-of-mass enters a stationary state,
reminiscent of a driven damped oscillator.Comment: 6 pages, 4 figure