Thermal Modeling of Hard Disk Drives

Abstract

A methodology for thermal modeling of hard disk drives (HDD) using a computational fluid dynamics (CFD) program that solves the conjugate (conduction and convection) heat transfer problem is presented. The methodology addresses assumptions, model construction, and boundary conditions, as well as measurement methods for determining key model inputs such as HDD component power. Computed results are compared to measurements at a range of heat input conditions, volumetric flow rates, and HDD sizes. It is shown that the model does well in predicting temperature trends. It is also shown that for first order approximations, to predict average base casting temperatures, the total HDD power with an average convective heat transfer coefficient can be used. Also noted is the importance of considering the heat path through the air gap between the brushless d.c. motor stator and rotor.