Transport of Oil in a Compound Vortex

Transport of immiscible admixtures in a compound vortex created by a uniformly rotating disk located at the bottom of the cylindrical container is investigated. At the initial time, a spot of a heavy dye or light oil is disposed at the centre of the free surface of water inside the cylindrical container. In the process of the compound vortex formation the marker admixture is partially immersed into the water body and is assembled into a body of revolution. On the free surface, the admixture spot loses the regular round shape, spiral arms are stretched out from the appeared protrusions and cusps. The orientation of these arms is opposite to the direction of fluid rotation in the container. Geometrical parameters of these structures for different flow regimes are studied.