Characteristics of heat transfer in small disk enclosures at high rotation speeds

Experimental results are reported for heat transfer in small disk enclosures containing several 5.25-in-diameter disks and two symmetrical brushless DC motors mounted on a spindle. The air flow over the disk is probably turbulent at a rotation speed of more than 5400 r.p.m., and windage loss dominates the total rotation loss. Effective forced convection reduces the temperature increase inside the enclosure. There is not much temperature dependence on disk position, because heat generation in the enclosure is symmetrical. Track densities of more than 100 tr/mm are shown to be feasible as a result of the small thermal off-tracking and head position deviation