Abstract
We investigate complex behavior of rotating flow in hard disk drive (HDD). The flow is driven by a stack of rotating disks mounted in a non-axisymmetric enclosure. The recent HDDs are equipped with more numbers of disks mounted in particular outer dimensions in order to fulfill the increased demands for higher storage capacity. As the increase of the number of the disks mounted in a single enclosure, the spacing between the disks has been reduced, and hence the gas flow has to go through narrower space in the complex internal geometry. In the present study, we focus on the flow behavior with different disk spacings in a simplified HDD model. The control of the disk spacings were realized by mounting either two or three disks in a non-axisymmetric enclosure. We performed flow experiments using the transparent HDD model and working fluid with matched refractive-index. Qualitative information on the flow was provided based on flow visualization, and quantitative information on the velocity fields was obtained using particle image velocimetry(PIV). Flow behavior is investigated between the disks at different sets of Reynolds numbers, angles of inserting arms and observation planes. We discuss on the evolution of the flow velocities at different circumferential angular positions.
