Self-excited vibrations of a flexible disk rotating on an air film above a flat surface

Self-excited vibration of a spinning flexible disk is studied to provide design guidance for high speed magnetic disk storage devices. The dynamic model includes coupling between vibrations of a rotating plate and waves in an incompressible viscous fluid film. A single-mode approximation is used to estimate the critical speed and the influence of the various disk and air-film parameters is noted. A simple physical explanation of the instability mechanism is given and the critical speeds for several disk configurations are estimated. More accurate numerical procedures are described and the results of calculations for a particular disk system are compared with the single-mode approximation.