Schematic view of the experimental setup.
(a) Steady shear rheology of the suspending fluid (solid diamonds) and particle volume fraction suspension (hollow triangles). (b) Elastic and loss moduli of the suspending fluid at 5% strain amplitude: (solid triangles), (solid squares), reversed (hollow triangles), and reversed (hollow squares).
Three images demonstrating radial particle drift during oscillatory flow with strain and . Particles used for drift velocity calculation are marked A, B, and C. The images were acquired (i) 1500 s, (ii) 6000 s, and (iii) after the start of oscillatory flow. The radial direction is vertically upward in the images.
Evolution of radial trajectories of the three particles shown in Fig. 3 at each time after the start of oscillatory flow. The time axis has the same meaning as in Fig. 3 above, without any shifting of the origin.
(a) Radial drift velocity and (b) radial displacement per cycle as a function of strain amplitude for oscillation frequencies of (solid squares) and (hollow squares).
(a) Radial drift velocity and (b) radial displacement per cycle as a function of oscillation frequency, strain amplitude . In (b), solid line represents the function and dashed line represents the function .
Normalized torque evolution curve: strain amplitude and .
(a) Normalized torque value as a function of strain amplitude, the ratio of final torque to initial minimum torque for (solid triangles) and (hollow squares), and the ratio of torque at a total strain of 1930 and initial minimum torque for (hollow triangles) and (x). Dashed line represents the calculated final torque ratio based on the fully developed concentration profile predicted by the suspension balance model. (b) Final/minimum torque ratio as a function of oscillation frequency, strain .
Measured radial drift velocity for oscillation frequencies of (solid squares) and (hollow squares) and strain amplitude of 0.415 (stars), compared to the estimated initial migration velocity in steady flow, based on the suspension balance model, at the same average velocities corresponding to the oscillatory flows (solid line). The estimated secondary flow velocity for a Newtonian fluid at low Reynolds number in the infinite plate limit (McCoy and Denn, 1971) is also shown (dashed line).
Parameters for oscillatory flow experiments.
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