Figure 2.

Calculated trajectories of a particle (d_p = 123 μm, ρ_p = 1.05 g/mL, ρ_f = 1 g/mL) in a rotating disc. The orange dashed line shows a trajectory of a free particle in a disc rotating around the point (0,0) in the counterclockwise direction with angular velocity ω = 800 rpm. A trajectory of the same particle in a rectangular chamber of 2 mm width (empty box) is modified: after the particle reaches the lateral wall of the chamber, it drifts under the action of the centrifugal force (red line). When an additional Euler force due to the angular acceleration (assuming linear increase of ω from 0 to 800 rpm in 0.5 s) is exerted on the particle, it moves backwards after reaching the wall (blue line).