Unsteady flow-induced vibration of the slider in a commercial hard disk drive

Abstract

This report presents a numerical investigations on the characteristics of Flow-Induced Vibration (FIV) of the Head Gimbal Assembly (HGA) in a working hard disk drive (HDD).The work has been carried out by the author over the past 2 semesters for his Final Year Project (FYP).

The numerical simulations are based on a simplified Large Eddy Simulation (LES) turbulent model of two-dimensional channel flow around a rectangular block. The model is evaluated with FLUENT platform and pressure and velocity fluctuations on several selected nodes around the HGA are investigated in the turbulent model for both time and frequency domain.

The results show that the pressure fluctuations around the HGA are highly associated with the FIV in terms of principle peaks around from 1.6 kHz, 2.7 kHz and 4.3 kHz. The spectrum results for the velocity fluctuation also correspond with those of pressure fluctuations around the principle peaks above. From the corresponding drag force which was calculated by the pressure difference between two nodes, it was found that it has a direct aerodynamic excitation of the FIV on the HGA

In conclusion, the spectrum characteristics of FIV on the HGA could be analysed through those of the pressure and velocity fluctuations around the HGA, which characterize the turbulent aerodynamic excitation for the FIV on the HGA in a working HDD.