Scientific Calendar Event



Description
Abstract:
Laboratory experiments with rotating and/or stratified fluids and numerical
simulations of 2D turbulence in bounded domains have been carried out to 
investigate the dynamics of quasi-2D turbulent flows in circular, square 
and rectangular containers. The dynamics of decaying and forced 2D turbulence
in domains bounded by no-slip lateral boundaries is strongly affected by 
vorticity production nearby the lateral no-slip walls. 
This process results in enhanced vortex production, in the generation of 
mean rotation of the flow (finally yielding a large central vortex in 
square domains), in modified energy spectra, in the potential destabilization
of the central vortex by the boundary layers, in anisotropy of the 
turbulence properties as reflected by structure functions and PDFs, etc. 
Laboratory experiments on the self-organisation of decaying quasi-2D 
turbulence have been carried out in two-layer fluids, in linearly 
stratified fluids and in shallow fluid layers (with strong bottom friction).
Forced quasi-2D turbulence has been studied in rotating fluids in order to 
measure the modification of the spectra by boundary-induced vorticity 
production. The different laboratory experiments and the mechanisms for 
boundary-induced vorticity production will be discussed. It will be shown 
that several observations from 2D turbulence simulations in bounded domains 
are confirmed by these experiments indicating that certain aspects of 
quasi-2D turbulence can well be predicted and understood by 2D flow dynamics. 
Go to day