Vortices in a rotating shear layer

Results from an experimental study of vortices in a rotating shear layer will be presented. Through the rotation of circular sections in the base and lid of a circular tank, a vertical shear layer is created in the fluid interior. In supercritical conditions, the flow is in the form of a regular string of two-dimensional, vertically uniform, vortices along the now wavy shear layer. Once established, the vortices are very stable flow structures that persist as long as the shear is maintained. Under most conditions the vortices were steady, but quasi-periodic and chaotic flows were also observed. The data from the experiments are in the form of maps of the instantaneous horizontal velocity field obtained by a particle tracking technique similar to Particle Image Velocimetry (PIV). The data would be useful validate both the spatial and temporal behaviour of numerical models.