Lagrangian Structure Functions in Turbulence: A Quantitative Comparison between Experiment and Direct Numerical Simulation

TL;DR

This paper compares experimental and numerical data on Lagrangian velocity structure functions in turbulence, achieving a detailed quantitative understanding of velocity scaling and intermittency across different scales and Reynolds numbers.

Contribution

It provides a comprehensive quantitative comparison between experimental and numerical Lagrangian turbulence data, clarifying previous discrepancies.

Findings

Good quantitative agreement between experiment and numerics for velocity increments

Intermittency varies with time lag and proximity to Kolmogorov scales

The study resolves previous disagreements between experimental and numerical results

Abstract

A detailed comparison between data from experimental measurements and numerical simulations of Lagrangian velocity structure functions in turbulence is presented. By integrating information from experiments and numerics, a quantitative understanding of the velocity scaling properties over a wide range of time scales and Reynolds numbers is achieved. The local scaling properties of the Lagrangian velocity increments for the experimental and numerical data are in good quantitative agreement for all time lags. The degree of intermittency changes when measured close to the Kolmogorov time scales or at larger time lags. This study resolves apparent disagreements between experiment and numerics.