Viscous Disk Air Flow Displacement Device (VDAFDD): Development and Performance

The development and performance of a unique viscous disk air flow displacement device (or VDAFDD) for inducing airflow in confined spaces is described. The development is motivated by electronic cooling, where limitations on space are especially severe and the need exists to circulate air over or through the key components using a compact and efficient device. To induce air motion, array of disks are employed with their axis of rotation perpendicular to the air stream. Results from the most successful prototype, which was developed and tested, prototype 2, are presented for Reynolds numbers up to 671 to illustrate nominal behavior, as well as behavior as a number of different parameters are altered, including the magnitude of exit flow restriction, the air gap above the disks, and the number of disks employed to induce air motion. Also discussed are the effects of disk rotational speed, comparisons with theoretical predictions, and one earlier prototype whose performance is significantly less than that of prototype 2.