Lagrangian Investigation of Two-Dimensional Decaying Turbulence

TL;DR

This paper numerically studies two-dimensional decaying turbulence from a Lagrangian perspective, analyzing particle trajectories, accelerations, and curvature to reveal universal self-similar behaviors in turbulent flows.

Contribution

It introduces a Lagrangian framework for analyzing 2D decaying turbulence, emphasizing particle trajectories, accelerations, and geometric properties, highlighting universal behaviors.

Findings

Strong signatures of self-similar universal behavior

Dominance of coherent structures in particle dynamics

Insights into acceleration and curvature statistics

Abstract

We present a numerical investigation of two-dimensional decaying turbulence in the Lagrangian framework. Focusing on single particle statistics, we investigate Lagrangian trajectories in a freely evolving turbulent velocity field. The dynamical evolution of the tracer particles is strongly dominated by the emergence and evolution of coherent structures. For a statistical analysis we focus on the Lagrangian acceleration as a central quantity. For more geometrical aspects we investigate the curvature along the trajectories. We find strong signatures for self-similar universal behavior.