The effect of broadband rotational velocity fluctuations on flows in spherical layers

We report the results of a numerical investigation of isothermal axisymmetric flows of a viscous incompressible fluid in rotating spherical layers in the presence of random small-amplitude oscillations of the rotational velocity of the inner sphere about the constant (in time) average value. Two cases are considered: the rotation of the inner sphere only and the corotation of spheres with equal angular velocities. It is established that, in these two cases, the flows respond to perturbations in different ways. Comparison with experiment confirms the possibility of an increase in the average velocity in separate areas of the flow with upon an increase in the amplitude of fluctuations, which has been detected in calculations.