LABORATORY EXPERIMENTS ON QUASI-2D TURBULENCE IN ROTATING AND STRATIFIED FLUIDS
Starts 5 Nov 2004 11:00
Ends 5 Nov 2004 20:00
Central European Time
ICTP
Main Building Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
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.