Measurement of local dissipation scales in turbulent pipe flow

TL;DR

This study experimentally measures the distribution of local dissipation scales in turbulent pipe flow across various Reynolds numbers, confirming universality and agreement with theoretical and simulation predictions.

Contribution

First experimental evaluation of local dissipation scale distribution in turbulent pipe flow across multiple Reynolds numbers, validating universality and theoretical models.

Findings

Distributions agree with simulations and theory

Universality of small-scale turbulence fluctuations

Consistent results at different flow regions

Abstract

Local dissipation scales are a manifestation of the intermittent small-scale nature of turbulence. We report the first experimental evaluation of the distribution of local dissipation scales in turbulent pipe flows for a range of Reynolds numbers, 2.4x10^4<=Re_D<=7.0x10^4. Our measurements at the nearly isotropic pipe centerline and within the anisotropic logarithmic layer show excellent agreement with distributions that were previously calculated from numerical simulations of homogeneous isotropic box turbulence and with those predicted by theory. The reported results suggest a universality of the smallest-scale fluctuations around the classical Kolmogorov dissipation length.