Physical Regimes and Dimensional Structure of Rotating Turbulence

Numerical simulations of rotating turbulence have given rise to “unexpected results”: An increasing Ω did not lead to the “expected” route to a 2D state. A recent model of turbulence leads to a new number N  =  K(νΩ)^-1 (K and ν are turbulent kinetic energy and viscosity) so that DNS (direct numerical simulation) and LES (large eddy simulation) correspond to N<1 and N>1. 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.