Of Large-Scale Vortical Structures Between Rotating Disks By Continuous PIV

In this study, we investigate the flow between co-rotating disks in a stationary cylindrical enclosure. Here, the gap between disks is much narrower than disk radius. This flow is often non-axisymmetrical and complicated. This flow sometimes induces magnetic-head oscillations in disk storage drives of PCs. Then, we carry out flow visualisations using a high-speed camera, and time-continuous quasi-three-dimensional PIV (Particle Image Velocimetry) analyses. As a result, we confirm a pair of toroidal vortex structures near the cylindrical enclosure on the rz plane. We show the toroidal structures on a quasi-three-dimensional space rzt. Here, t is the time. By this visualisation technique, we can easily and clearly see the toroidal structures. We can confirm that the vortex structures hardly fluctuate.