ROTOR WHIRL MEASUREMENTS ON A LONG ROTATING CYLINDER PARTIALLY FILLEDWITH LIQUID

A theoretical analysis of along flexibly suspended, rotating cylinder partially filled with liquid has been presented earlier (Colding-Jorge nsen, 1990). Special emphasis has been placed on dynamic stability, ap plication in centrifuges, and the influence of external damping. The p resent paper presents experimental results for comparison with the the oretical analysis, especially in regard to unstable speed ranges, whir l speed relative to rotational speed, and limit cycle amplitudes with external damping. The theory agrees quantitatively with regard to spee d ranges and whirl frequency ratios but only qualitatively with regard to whirl amplitudes, indicating the need for further development of t he nonlinear analysis of the fluid motion with external damping.