Nonuniversal features of forced two-dimensional turbulence in the energy range

We examine energy spectra, fluxes, and transfers of two-dimensional forced incompressible turbulence with linear drag in the energy range, and find marked departures from 5/3 law and the idea of locality. Any attempt to bring the system into the "ideal cascade state" would result either in spectral (bulge) or flux distortion. We corroborate this observation by DNS (spectral code) and eddy-damped quasinormal Markovian simulations. We examine the energy peak wave number k(p), in terms of drag coefficient lambda, and energy dissipation rate epsilon, and find a relation k(p) approximately C(lambda(3)/epsilon)(1/2) to hold with C approximately 50, but only within a limited range of parameters.