TOWARDS A 2-FLUID PICTURE OF INTERMITTENCY IN SHELL MODELS OF TURBULENCE

Intermittency in the Gledzer-Okhitani-Yamada model of turbulence is ex plained in terms of collisions of coherent solitonlike structures with a random background issuing from the disintegration of their predeces sors. This two-fluid picture is substantiated by the elucidation of lo cal dynamical mechanisms leading to anomalous growth of coherent struc tures, their detection in true signals involving forcing and dissipati on, and an investigation of their statistics.