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A Turbulence Reduction Scheme for Sealed Rigid Disk Files

IP.com Disclosure Number: IPCOM000108400D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 50K

Publishing Venue

IBM

Related People

Munce, AC: AUTHOR [+2]

Abstract

The flow turbulence between co-rotating disks is a major source of flow-induced slider flight-height modulation. A general scheme with several variations of implementation to suppress the flow turbulence is described and demonstrated.

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A Turbulence Reduction Scheme for Sealed Rigid Disk Files

      The flow turbulence between co-rotating disks is a major source
of flow-induced slider flight-height modulation.  A general scheme
with several variations of implementation to suppress the flow
turbulence is described and demonstrated.

      A unique characteristic of the flow between shrouded,
co-rotating disks, like those in rigid disk drives, is that the
fluctuating velocity field is contributed strongly by an organized
flow structure which extends from a critical radius (approximately
the middle radii of the disk data band) to the outer radius of the
disk.  Experimental data indicates the radial extent of the organized
flow structure is insensitive to the rotation rate of the disks.  In
contrary to intuition, the presence of a linear, rectangular arm
between co-rotating disks results in lower turbulence levels.  This
reduction of turbulence arises because obstruction between the disks
prohibits the formation of the organized flow structure.

      This disclosure utilizes this principle by optimally placing a
rectangular obstacle, extending from the stationary shroud, between
co-rotating disks.  A maximal reduction in the aerodynamic loading is
achieved when the r/w arm and the turbulence reducer are 180 degrees
apart. The reason is that both the read/write arm and the turbulence
reducer are not in the turbulent wake of the others.  In addition,
the redevelopment of the organized flow str...