Characterization of Q2D rotating turbulence evolving over a no-slip bottom

Samenvatting

This study discusses the characterization of Q2D rotating turbulence evolving over a no-slip bottom. Numerical simulations and laboratory experiments showed an asymmetric decay of cyclonic and anticyclonic vortices that constitute the flow. This asymmetry is due to non-linear Ekman effects, which are responsible for the squeezing and, because of conservation of angular momentum, slower damping of anticyclonic vorticity. Furthermore, the numerical simulations showed that although an asymmetry exists, the evolution of the total number of vortices, the mean area of the vortices, and the total area of the vortices are independent of the non-linear Ekman effects. In contrast, these effects modify the evolution of quantities related to the vorticity such as the vorticity skewness, the vorticity kurtosis, and the typical length scale given by the ratio of the enstrophy and the kinetic energy. Moreover, the experiments showed the appearance of meandering currents with a preferential direction, which are not observed in the numerical simulations and may be due to different three-dimensional effects.

Datum prijs	31 okt. 2008
Originele taal	Engels
Begeleider	Matias Duran Matute (Afstudeerdocent 1), Ruben R. Trieling (Afstudeerdocent 2) & G.J.F. van Heijst (Afstudeerdocent 2)