Vortex Evolution in Realistic Geophysical Flows.
Abstract
Laboratory experiments and numerical simulations of vortex evolution in realistic geophysical flows are reported. Two laboratory experiments are discussed. The first experiment examined three dimensional vortices produced from a wing in a nonstratified nonsheared flow. This study showed that vortices can migrate farther and last longer than previously reported. The second laboratory experiment investigated the evolution of two dimensional vortices in a stratified shear flow. This experiment showed the evolution of a solitary vortex when the background Richardson number was around four or less. Circulation estimates were also obtained for these vortices and showed a more rapid decay of circulation of the countersign vortex. Two numerical studies are also reported. In the first numerical study, we examined the evolution of a two dimensional vortex pair in a stratified shear flow. This study showed that the vortex pair evolved into a solitary vortex when the ambient Richardson number was on the order of unity or less. A second numerical study used a k-epsilon model to examine the evolution of a two dimensional vortex pair. It was found that the standard k-epsilon model did a poor job of representing the turbulent dissipation in vortex flows. Good agreement with experimental results was obtained with this model with a reduction in the eddy viscosity coefficient.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 08, 1996
- Accession Number
- ADA324597
Entities
People
- Donald P. Delisi
- Robert E. Robins
Organizations
- Northwest Research Associates