Flow Visualization and Assessment of the Particle Image Velocimetry (PIV) Analysis Based on Cylindrical Coordinate for the Rotating Flow Driven by Corotating Disks Mounted in a Non-axisymmetric Enclosure.

Abstract

In preceding research work made by scientists, the fluid flow driven by stacked corotating disks inside a container such as hard disk drive (HDD) for information storage device is known to be complicated, highly unsteady, and three-dimensional. During the measurement by particle image velocimetry (PIV) concept, we have discussed the results obtained and analyzed in the orthogonal coordinate system for the rotating flow which was transformed into the cylindrical coordinate system. In this study, we apply refractive index matching (RIM) to a simplified HDD model, perform flow visualization and PIV measurements in different insertion angle of the read and write arm (RWA). Behavior of this flow fields are then studied and reported at all areas visible during the experiment. The particle images in the orthogonal coordinate system are mapped to the cylindrical coordinate system, the PIV analysis is directly promoted in the cylindrical coordinate system, the velocity distribution and vorticity are calculated, and the comparison with the conventional method is verified.