An experimental study of forced asymmetric oscillations in a rotating liquidfilled cylinder
Abstract
An experimental study was made of forced asymmetric oscillations in a liquidfilled, rapidlyrotating, right circular cylinder. Oscillations were forced by causing the cylinder to cone about an axis passing through the center of the cylinder but offset by a small angle from the axis of rotation; the motion is similar to precession of a gyrostat but constrained to fixed frequency and amplitude. The fluctuating pressure response of the liquid in the cylinder was measured using pressure transducers mounted in an end wall. Fluctuating pressure was measured for nondimensional coning frequencies of .030 to .075, for coning angles of .00018 x .035 radians, and for Reynolds numbers of 5,000 to 500,000. Comparisons were made to existing linear theories of the liquid response. The results agreed with theoretical predictions at the highest Reynolds number, and smallest angles. At the smallest Reynolds number, the data agreed better with the solution of a forced oscillation problem than with the solution of a free oscillation problem. At coning angles as small as .0005, the data showed significant departure from the predictions of linear theory, and at coning angles as small as .0008, the liquid exhibited nonstationary behavior suggestive of a flow instability.
 Publication:

Final Report Ballistic Research Labs
 Pub Date:
 October 1981
 Bibcode:
 1981brla.rept.....W
 Keywords:

 Forced Vibration;
 Liquid Filled Shells;
 Nonstabilized Oscillation;
 Oscillating Cylinders;
 Rotating Cylinders;
 Axes Of Rotation;
 Circular Cylinders;
 Eigenvalues;
 Flow Measurement;
 Flow Stability;
 Linear Systems;
 Nonlinear Systems;
 Projectiles;
 Reynolds Number;
 Fluid Mechanics and Heat Transfer