Abstract
Particle motions within isolated mixing regions (IMRs) were experimentally investigated at low Reynolds numbers. The trajectories of resin particles (density: 1377–1663 kg/m3; diameter: 5 mm) were analyzed using image processing techniques. The effect of particle motion on mixing was also investigated by the decolorization of fluorescent green dye by acid-base neutralization. After a particle was captured within an IMR, it moved along various torus orbits within the IMR. The radius of secondary circulation of the particle varied between 6–17.3 mm. It is speculated that this change in the radius enhances the exchange of material between an IMR and the surrounding active mixing region.
