Decreasing Airflow Velocity in Hard Disk Drives with a Spoiler and Bypass

Abstract

High-speed disk rotation of hard disk drives (HDDs) produces high-speed airflow, which causes disk vibration called disk flutter, and vibration of the head carriage arm. These vibrations have a significant effect on the positioning precision of the head and should be reduced by considering aerodynamic factors. The airflow changes in HDD with a bypass and a spoiler were clarified by LES and PIV . These analyses show that a spoiler reduces the arm vibration by decreasing the flow velocity near the arm, in particular, decreasing the average flow velocity between the disks, diversing the flow into the bypass channel, and moving the high-speed-flow area toward the inner radius area of the disks.