Experimental Investigation of the Flow With a Free Surface in an Impulsively Rotating Cylinder

An experimental investigation was made of the impulsive spin-up from rest of a liquid in a partially filled cylindrical container. The main impetus was placed on delineating the effects of the presence of a free surface on the transient development of flow. Of particular interest were the situations in which the free surface intersected either or both of the endwall disks during the course of spin-up. Extensive flow visualizations were carried out by using suspended metal particles. An image processing technique was utilized to determine accurately the propagating velocity shear front as well as the time-dependent free surface contour. Precise measurements of the fluids velocities were obtained by using a laser Doppler velocimeter. The transient velocity profiles were mapped out, and they were found to be in satisfactory agreement with the predictions based on the simplified analysis. The radial location, Rs(t), of the propagating shear front was measured by applying the image processing technique to the visualized azimuthal flow field. The experimental data were found to be consistent with the numerical predictions.