Physical Regimes and Dimensional Structure of Rotating Turbulence

Numerical simulations of rotating turbulence have given rise to “unexpected results”: An increasing $\Omega$ did not lead to the “expected” route to a 2D state. A recent model of turbulence leads to a new number $N=K(\nu \Omega {)}^{-1\mathrm{}}$ (K and ν are turbulent kinetic energy and viscosity) so that DNS (direct numerical simulation) and LES (large eddy simulation) correspond to $N<\mathrm{}1\mathrm{}$ and $N>\mathrm{}1\mathrm{}$. In the first case, the energy cascade is suppressed, while in the second case there exists an inertial spectrum which is an equilibrium of quasi–2D-3D modes. With these ingredients, we reproduce DNS and LES data.