Lagrangian statistics in forced two-dimensional turbulence

TL;DR

This paper investigates the statistical behavior of tracer particles in forced two-dimensional turbulence, revealing a transition from non-Gaussian to Gaussian velocity fluctuations and analyzing acceleration correlations to understand underlying dynamics.

Contribution

It provides new insights into Lagrangian statistics in 2D turbulence, including the transition of velocity fluctuation distributions and detailed acceleration correlation analysis.

Findings

Velocity PDFs transition from non-Gaussian to Gaussian

Acceleration correlation functions elucidate tracer dynamics

Comparison with 3D turbulence highlights differences

Abstract

We report on simulations of two-dimensional turbulence in the inverse energy cascade regime. Focusing on the statistics of Lagrangian tracer particles, scaling behavior of the probability density functions of velocity fluctuations is investigated. The results are compared to the three-dimensional case. In particular an analysis in terms of compensated cumulants reveals the transition from a strong non-Gaussian behavior with large tails to Gaussianity. The reported computation of correlation functions for the acceleration components sheds light on the underlying dynamics of the tracer particles.