Abstract
Fundamental frequencies and characteristics of four types of disturbance in the flow between a rotating inner and a stationary outer sphere are clarified by flow visualization and spectral studies of both scattering intensity power spectra and velocity power spectra. The dependencies of the fundamental frequencies on meridional angle θ and Reynolds number Re are considered. Consequently, it is found that fS, fW, fH and fB are fundamental frequencies characterizing spiral Taylor-Gortler (T. G.) vortices, travelling azimuthal waves of toroidal T. G. vortices, shear waves within the Ekman boundary layer and an up-down fluctuation of toroidal T. G. vortices, respectively, and are independent of θ and Re. Further, the fundamental frequencies are discussed in comparison with those of a flow between two concentric cylinders with the inner one rotating.
