Numerical simulation of positioning error caused by air-flow-induced vibration of head gimbals assembly in hard disk drive

Unsteady airflow in an actual hard disk drive (HDD) which has a rotary actuator is numerically simulated by using the large eddy simulation technique, and the aerodynamic force affecting head gimbal assembly (HGA) is estimated from the simulation. The calculated force is fed to a structure analysis to predict the airflow-induced vibration of the HGA. The authors calculate the head positioning error or the head displacements for the different HGA orientations to explain and classify the mechanism of airflow-induced positioning error (i.e., windage) in HDD.