INVERSE ENERGY CASCADE IN STATIONARY 2-DIMENSIONAL HOMOGENEOUS TURBULENCE

Direct numerical simulations with up to 1024(2) resolution are performed to study statistical properties of the inverse energy cascade in stationary homogeneous two-dimensional turbulence driven by small-scale Gaussian white-in-time noise. The energy spectra for the inverse energy cascade deviate strongly from the expected k-5/3 law and are close (somewhat flatter) to k-3. The reason for the deviation is traced to the emergence of strong vortices distributed over all scales. Statistical properties of the vortices are explored.