New features of swirling jets

Typical features of swirling flows include the development of recirculatory zones, two or more states occurring at the same values of control parameters, and jump transitions between flow states. Although these effects are of both fundamental and practical interest, being observed in tornadoes, over delta wings of aircraft, and in vortex devices, there is still no consensus on the explanation of their mechanisms. A v approximately 1/zⁿ solutions is developed which provide a satisfactory approximation of the velocity distribution in a vortex core, although these solutions cannot model the entire velocity field of practical flows. Because of this serious limitation, the practical applicability of the feature needs further theoretical and experimental studies.