Description of a standardized measurement set-up to test the thermal behaviour of disk drives under well-defined forced convection boundary conditions

This paper describes design and operation of a small wind tunnel to measure thermal behavior of DVD and CD drives under well-defined boundary conditions. Presently it is common practice that these measurements are performed either under free convection conditions or in some type of convection oven with unknown airflow conditions. It is proposed to use the measurement set-up in order to obtain after calibration the thermal resistance of critical components in the disk drive as function of average airflow along the encasing of the drive. The measurement set-up consists of a Perspex box with a standard 60 mm fan mounted in the back. A disk drive is mounted in the center of the box. The measurement set-up was designed using a commercial CFD code. The design goal is to obtain a standardized measurement set-up to measure a disk drive where test velocities can be set from 0.1 to 3 m/s, using only cheap components. After design the measurement set-up was build and measurements were carried out on a DVD drive for various air speeds and power settings. These results can be used for instance to benchmark a DVD drive mounted in a DVD recorder application. The temperatures measured in the application are compared to the results for the wind-tunnel set-up. In this way an effective air velocity can be derived for the drive mounted in the application and possible design options for the cooling system can be compared to the benchmark.