LAGRANGIAN CORRELATION AND SPECTRA IN 2D TURBULENCE

Abstract

Transition from chaotic flow to turbulent flow is investigated in both the Eulerian and Lagrangian frame of reference. Eulerian spectra of the kinetic energy of the flow show the development of a hierarchy of scales, generation of a broad k-5/3 spectral range in developed turbulence. In the Lagrangian frame, single particle displacement is dominant by multiple scales for the chaotic flow. In fully developed turbulence, one single scale determines the transport properties, which is related to the most persistent scale in the system, the forcing scale.