|
科学通报(英文版) 2005
An experiment study of lee vortex with large topography forcingKeywords: towing tank,lee vortex,rotating and stratified flow,large obstacle Abstract: This paper, relates the lee vortex which is trig- gered when the rotating and stratified flow passes over the large obstacle by using towing tank and based on the simi- larity. The results show that Froude number Fr is the most important parameter, and, in the rotating case, the lee vortex is easily triggered, because the rotating may, on one hand, lead to downward flow, on the other hand, induce lee vortex through generating geostrophic vorticity. Even in the non-rotating case, the lee vortex can be still formed, as long as both Froude number Fr and stratification parameter N are appropriate. For the formation mechanism of the lee vortex, there are obvious differences in the rotating case compared with the non-rotating case. In the non-rotating case, the tilting term of the perturbation vorticity is a domi- nant factor of inducing the lee vortex. However, in the rotat- ing case, effect and the convergence of perturbation vorticity are dominant factors.
|