Air flow simulation of 1.8 in hard disk drive

Abstract

The simulation model is constructed base on precisely actual dimension of current 1.8-in hard disk
drive in the market with 3600 rpm rotation speed. Investigation of static pressure, velocity and flow behavior
have been performed among actuator arm position of inner diameter (ID), middle diameter (MD) and outer
diameter (OD) using RNG k-epsilon turbulent model. The numerical results shown how the air is brought
inward to the centre of rotating disk and how the air is thrown outward toward disk edge. At the different
actuator arm position, the static pressure, velocity and flow behavior are different. For instance, the pressure
profile acting on the media forms the arm like profile when actuator is at ID and the pressure acting on media
decrease when the actuator arm is at OD, the air flows along Head Gimbal Assembly (HGA) axis when the
actuator is at OD and flows across HGA axis at ID, dispersion of the air due to the ramp load emerged into
rotating disk region is also different when the actuator is at different position. These results help to predict the
vibration of the actuator arm and the performance of recirculation filtering.