Turbulent flow formation in a spherical layer at a variable velocity of rotation of the outer spherical boundary

Transitions to turbulent flow regimes in a layer of a viscous incompressible fluid confined between counterrotating spherical boundaries have been experimentally studied in the case of periodic variations in the outer sphere rotation velocity at a constant velocity of the inner sphere. A periodic flow regime formed during the rotation of spherical boundaries at constant velocities in the opposite direction is under consideration. The effect of the amplitude and frequency of modulation of the velocity of outer sphere on the transition from this regime to chaos has been determined. Based on the results of flow visualization and flow velocity measurements by the laser Doppler anemometry technique, it is shown that turbulent flows with spatiotemporal intermittency can be formed in the spherical layer.