Formation and break-down of large-scale vortices in 2D confined turbulence

Laboratory experiments 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. In this talk the formation and break-down of large-scale vortices and the anisotropic character of the turbulent flow will be addressed.