EXPERIMENTAL INVESTIGATION OF THE NATURAL -MODES OF IMMISCIBLE ROTATING FLUIDS IN A CYLINDRICAL RAPIDLY ROTATING VESSEL SUBJECT TO AXIAL EXCITATION

The natural modes and natural frequencies of two-phase immiscible flui d systems, enclosed in an axially excited and rapidly rotating cylindr ical vessel, are studied in dependence of the fluid system, the geomet ry and the filling ratio. The undisturbed cylindrical interface, being parallel to the direction of gravity, is generated by a high rotation al frequency. Due to an axial excitation a disturbance of the interfac e occurs. The resulting natural modes are documented photographically. In order to investigate the experimental imental data, dimensionless numbers (Bond number and Weber number) are introduced and plotted on p aper with logarithmic scale on both axes. Parameters are the rotationa l frequency and the thickness of the fluid layer. The plots show a lin ear relationship between Bond number and Weber number. The experimenta l method and the results are discussed critically.