Influence of the static field on a heavy body in a rotating drum with liquid.

The behaviour of a heavy cylindrical body in a rotating horizontal cylindrical cavity filled with viscous liquid is investigated experimentally. Several modes of the body behaviour depending on the rate of the cavity rotation, i.e., the ratio of the centrifugal force of inertia and the gravity, are detected. At a fast rotation rate, the body makes the solid-body rotation, remaining immobile relative to the cavity due to the action of the centrifugal force. In the absence of rotation, under the influence of gravity, the body occupies a position in the lower part of the cavity. At slow uniform rotation rate, the body is dragged by the cavity boundary and shifts to some angle relative to the initial position. With an increase in the rotation rate, the body is repulsed from the cavity boundary and occupies a suspended position, stationary in the laboratory frame, at a certain distance from it. In the suspension regime and the partial repulsion regime, which precedes it, the body performs auto-oscillations that resemble the precession. The flow structures near the suspended cylinder are studied using the PIV method.