Disappearance phenomena of velocity fluctuation in the transition of spherical Couette flow

In order to study on disappearance phenomena of velocity fluctuation in the laminar-turbulent transition of spherical Couette flow with only an inner sphere rotating, we measured azimuthal component of velocity fluctuation at the equator for various clearance ratios β=0.06∼0.206, and considered the evolution of correlation dimension d, maximum Lyapunov exponent λ and power spectra of the azimuthal velocity component with an increase of the rotating Reynolds number Re for each β. Consequently, the following conclusions were obtained. The disappearance phenomena occur only for β ≒ 0.13∼0.17. Even though d ≒ 2, no T² torus appears in the case of λ > 0. The kinetic energy of disturbance increases with Re in the range of higher frequencies in the case of β where the disappearance phenomena do not occur, but decreases to almost zero in the case where they occur.