Experiments on the stability of conical and cylindrical liquid columns at low Bond numbers

A low Bond number simulation technique was used in conducting a number of experiments to establish the stability limits of cylindrical and conical floating liquid columns under conditions of isorotation, equal counter-rotation, rotation of one-end only, and parallel-axis offset. Tests which establish the conditions for resonance in cylindrical liquid columns perturbed by axial, sinusoidal vibration of one end-face are also reported. All tests were carried out under isothermal conditions with water and silicone fluids of various viscosities. With few exceptions, test data for rotating columns show that the onset of instability is in the C-mode and is correlated very well by a theoretical prediction based on isorotation. The onset of instability for a cylindrical column of silicone fluid having a viscosity 100 times of water under equal counter-rotation and single end-rotation is in the first asymmetric mode. An explanation for the rather surprisingly simple C-mode correlation is provided by the results of flow visualization studies. The data on the resonance of cylindrical columns are correlated very well by a prediction based on theory.