Thermally induced, nonlinear vibrations of rotating disks

The natural frequency and responses for the nonlinear free vibration of heated rotating disks are presented analytically when nonuniform temperature distributions pertaining to the laminar and turbulent airflow induced by disk rotation are considered. The nonuniform temperature distributions on the disk are highly dependent on its rotation speed. The natural frequencies for symmetric and asymmetric responses of a 3.5 inch diameter computer memory disk are calculated. When the disk is heated, its stiffness becomes larger for the two lowest nodal diameter numbers and smaller for the other nodal diameter numbers. It implies that the vibration of heated, rotating disks for the higher nodal diameter numbers may be induced more easily than the cooled one. The results for the nonlinear vibration can reduce to those for the linear vibration when the nonlinear effects vanish. To further investigate of the interaction of thermal and nonlinearity of rotating disks, the temperature distribution for such a rotating disk needs to be developed.