Rotor Whirl Measurements on a Long Rotating Cylinder Partially Filled With Liquid

Abstract

A theoretical analysis of a long flexibly suspended, rotating cylinder partially filled with liquid has been presented earlier (Colding-Jo̸rgensen, 1990). Special emphasis has been placed on dynamic stability, application in centrifuges, and the influence of external damping. The present paper presents experimental results for comparison with the theoretical analysis, especially in regard to unstable speed ranges, whirl speed relative to rotational speed, and limit cycle amplitudes with external damping. The theory agrees quantitatively with regard to speed ranges and whirl frequency ratios but only qualitatively with regard to whirl amplitudes, indicating the need for further development of the nonlinear analysis of the fluid motion with external damping.