Thermal Characteristics of Enterprise-Class Hard Disk Drives

Experiments have been carried out to investigate the thermal characteristics of enterprise-class hard disk drives (HDD). The experimentally determined windage loss, internal air velocity, flow core temperatures, surfaces temperatures, and heat transfer coefficients of the HDDs cover are discussed. The Reynolds shear stresses and turbulent heat fluxes of the airflow in the hard disk enclosure have also been measured. Findings indicate that the rise of temperatures in the HDD during frequent seeking is not merely attributed to the drawing of additional current by the voice coil motor. It has also been found that a sudden drop in the internal surface high heat transfer coefficient, which the HDD is dependent on for efficient heat dissipation, is correlated to a sudden decline of turbulent heat fluxes in the enclosure air of the HDD. This decline is probably a consequence of flow turbulence suppression caused by seeking.