Trailing vortices in stratified fluids
Johnson, S. K.
MetadataShow full item record
Experiments were conducted with two Delta wings and a streamlined body with lifting surfaces to investigate the evolution of turbulent trailing vortices in stratified and unstratified water. The vortex trajectories were determined as a function of the relative depth D/b sub o, normalized time V sub o t/b sub o, and the stratification parameter Nb sub o/V sub o. The results have shown that the vortices rise only to a finite height as they gradually demise under the influence of turbulence, sinusoidal instability, and the vortex breakdown. The effect of stratification is to reduce the lifespan of vortices and the maximum height attained by them. Various approximate analyses have been examined and new ones have been proposed to determine the lifespan of the vortices. Finally, an exploratory numerical analysis of the two-dimensional, unsteady laminar vortices has been carried out with encouraging results. (Author)
NPS Report NumberNPS-69-82-003
Showing items related by title, author, creator and subject.
Elnitsky, John II. (1987-09);The trailing vortices generated by the control planes of submarines give rise to surface signatures in the form of scars and striations. Two counter-rotating vortices were generated in a novel experimental system and their ...
Effect of vortex circulation on injectant from a single film-cooling hole and a row of film-cooling holes in a turbulent boundary layer, Part 2: injection beneath the vortex upwash Kaisuwan, Pisut (Monterey, California. Naval Postgraduate School, 1989-12);Results are presented which illustrated the effects of single embedded longitudinal vortices on heat transfer and injectant downstream of a row of film-cooling holes and downstream of a single hole in a turbulent boundary ...
Lorfeld, David J. (Monterey, California. Naval Postgraduate School, 2017-12);Detection and tracking of submarines by acoustic means alone has become increasingly difficult due to quieter submarines, which underscores the need for non-acoustic detection methods. One hydrodynamic method available is ...