Flow visualization and spectral measurements in a simulated rigid disk drive

An experimental simulation of the fluid mechanics of a rigid disk drive has been performed matching the geometry and Ekman number of a full-size (14 in.) disk drive. Three different flow configurations have been studied. The first was a simplified geometry used to determine the basic structure of the flow. The second case explored the effect of the introduction of cooling flow into the basic geometry, and the third considered the separate effect of the blockage due to the presence of the supports for the read heads. All three cases exhibited flow regimes near the rotating hub which were distinct from the flow farther from the hub. In addition, each of the flow configurations contained features not found in the other cases. The implications of these flow features with respect to disk drive performance are discussed