The kinetic energy spectrum of the two-dimensional enstrophy turbulence cascade

A direct numerical simulation of forced two-dimensional turbulence with hyperviscosity is performed at resolution 4096(2). A stage is reached at which the flux of enstrophy from large to small scales is approximately constant in time. The cubic and quintic relations for the third-order velocity structure function derived by Lindborg [J. Fluid Mech. 388, 259 (1999)] are verified. The calculated kinetic energy spectrum in the constant enstrophy flux range has the form E(k)=K epsilon(omega)(2/3)k(-3), where epsilon(omega) is the enstrophy dissipation. This is in accordance with the prediction of Kraichnan [Phys. Fluids 10, 1417 (1970)] and Batchelor [Phys. Fluids 12, II233 (1969)]. The logarithmic correction, suggested by Kraichnan [J. Fluid Mech. 47, 525 (1970)], is not present in the calculated spectrum. (C) 2000 American Institute of Physics. [S1070-6631(00)01905-X].