Study of the Flow Induced by Rotating Disk Stack in a Non-Axisymmetric Enclosure

(on the Flow Behavior in the Disk Region based on the Measurements with Particle Image Velocimetry)

Abstract

We report on the experimental study on the complex behavior of the fluid flow induced by a pair of coaxially rotating disks in a non-axisymmetric enclosure, which is commonly encountered in a hard disk drive. We focused mainly on the flow behavior in the disk region based on a series of measurements with particle image velocimetry. The experiment was carried out using refractive-index matched transparent model consists of a pair pf rotating disks with alternately inserted arms in a non-axisymmetric enclosure. The measurements were performed at four angles of the arm insertion on two observation planes at two Reynolds number conditions. Velocity vector fields parallel to the disk surfaces were obtained and we analyzed the circumferential and radial components of the flow velocities. Furthermore, differential parameters including vorticity and shear rate were calculated. The results reveal that the flow is largely influenced by the different angles of the arm insertion.