Structure Optimization Study of Hard Disk Drives to Reduce Flow- Induced Vibration

Abstract

Abstract:In this paper, the effects of two flow-induced vibration (FIV) mitigation components on hard disk drive (HDD) airflow, vortex splitters and flow diverters, were verified. The edges of the components were also modified by filleting and the resulting effect on airflow determined. A perspective review on HDDs and their operation, and the mechanism and mitigation of FIV was discussed. Three suitable turbulent models from the commercial fluid flow solver FLUENT were briefly compared. A preliminary study was then carried out on a simplified HDD model to determine the mesh fineness required in HDD turbulent flow simulation in order to obtain accurate results. Another study was done to compare between the RNG k-and LES turbulent models in FLUENT. A full 3.5 inch commercial HDD model was used and results indicated that the LES model was suitable for turbulent flow modelling of a HDD. Lastly, flow simulation of three HDD models with different FIV mitigating features was carried out. Results showed that flow diverters are effective in reducing airflow turbulence in HDD for Re of 12.5x10 4 . The modification and filleting of component edges to make them more aerodynamic streamlining was shown to be less effective but further studies should be done to conclude on the effectiveness of filleting. An optimized HDD structure which includes both vortex splitters and flow diverters, with the filleting of component edges recommended but not mandatory was proposed.

Numerical Investigation of Airflow Pattern inside Environmental Chamber

“…It was employed to study the trajectories of spherical and tetrahedral particles in a 3.5 HDD [6]. For a dual platter HDD, an RNG k-ε model and a Large Eddy Simulation (LES) model were used to investigate its airflow behavior and the effect of its two flowinduced vibration (FIV) mitigation components [7]. Recently, we applied a standard, an RNG and a realizable k-ε turbulence model to predicting the airflow inside a 3.5 dual platter HDD [8].…”

CFD Investigation of Damper Plate Effect on Air Flow in High Speed Rotation Hard Disk Drive by Using K-E with a Partial Model

“…(1) Increased rotation speed results in the head stack assembly (HSA) experiencing a higher force from air flow. An air damper is used to smooth the flow by insertion between the rotating disks [6] and to reduce the RMS velocity that brings reduced flow induced vibration (FIV) of the HDD [7,8]. Its dimensions have been studied by the Laser Doppler Vibrometer (LDV) experiment [9].…”