Transition from deep to shallow water layer: formation of vortex dipoles
Langue
en
Article de revue
Ce document a été publié dans
European Journal of Mechanics - B/Fluids. 2005, vol. 24, p. 19-32
Elsevier
Résumé en anglais
In this paper we study the transition from a deep to a shallow water layer and the formation of quasi-two-dimensional vortex dynamics. Vortices are experimentally generated by a circular horizontal turbulent pulsed jet. ...Lire la suite >
In this paper we study the transition from a deep to a shallow water layer and the formation of quasi-two-dimensional vortex dynamics. Vortices are experimentally generated by a circular horizontal turbulent pulsed jet. The dimensional analysis gives two relevant dimensionless parameters: the jet Reynolds number $Re$ and a number $C$ which characterizes the vertical confinement. They are respectively defined by $Re=Q/\nu$ and $C=(Q/H^2)t_\text{inj}$ ($H$ is the water depth, $\nu$ is the kinematical viscosity, $Q$ the injected momentum flux and $t_\text{inj}$ the injection duration). Experimental results show a strong influence of $C$ on the flow: when $C<1$, the evolution is a typical three-dimensional turbulence decay, while when $C>2$ we observe the formation of large vortex dipoles. However these dipoles are not strictly two-dimensional because of the presence of a vertical circulation in the front of the dipole. Results are independent of the jet Reynolds number in the range $1000< Re< 1800$. In addition, a comparison between experimental shallow water dipoles and theoretical model is exposed.< Réduire
Mots clés en anglais
Shallow water
Experiment
Vortex dipole
Quasi-two-dimensional turbulence
Origine
Importé de halUnités de recherche