NONLOCAL TRIAD INTERACTIONS AND THE DISSIPATION RANGE OF ISOTROPIC TURBULENCE

Detailed transfer functions T(k\p,q), which express turbulent energy transfer rate to modes k caused by their nonlinear interactions with modes p and q, are analyzed using results of direct numerical simulations of homogeneous turbulence. A previously found phenomenological scaling for the functions T(k \p,q), which brings them into a self-similar form, is used to deduce the form of the energy spectrum in the dissipation range proportional to k-2exp(-ak) and the transfer spectrum proportional to exp(-ak). A physical mechanism of the energy transfer process consistent with the self-similarity scaling is proposed.