Lagrangian acceleration and its Eulerian decompositions in fully developed turbulence

Abstract

The acceleration of a fluid particle, given by the Navier-Stokes equations, is a key quantity in the study of turbulence, both from Lagrangian and Eulerian viewpoints. It is well known that, due to small-scale intermittency, acceleration statistics deviate from Kolmogorov's mean-field hypotheses. Using theoretical analysis and a massive direct numerical simulation database, we investigate the intermittency of Lagrangian acceleration in terms of its underlying Eulerian decompositions. We find that their intermittency is even at odds with standard multifractal models, because of strong underlying correlations, which can be otherwise explained by simple theoretical arguments.

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