Extending Kolmogorov Theory to Polymeric Turbulence

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Chiarini, Alessandro, Singh, Rahul K., Rosti, Marco E.
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866917801165324288
author Chiarini, Alessandro
Singh, Rahul K.
Rosti, Marco E.
author_facet Chiarini, Alessandro
Singh, Rahul K.
Rosti, Marco E.
contents The addition of polymers fundamentally alters the dynamics of turbulent flows in a way that defies Kolmogorov predictions. However, we now present a formalism that reconciles our understanding of polymeric turbulence with the classical Kolmogorov phenomenology. This is achieved by relying on an appropriate form of the Kármán-Howarth-Monin-Hill relation, which motivates the definition of extended velocity increments and the associated structure functions, by accounting for the influence of the polymers on the flow. We show, both analytically and numerically, that the ${\rm p}$th-order extended structure functions exhibit a power-law behaviour in the elasto-inertial range of scales, with exponents deviating from the analytically predicted value of ${\rm p}/3$. These deviations are readily accounted for by considering local averages of the total dissipation, rather than global averages, in analogy with the refined similarity hypotheses of Kolmogorov for classical Newtonian turbulence. We also demonstrate the scale-invariance of multiplier statistics of extended velocity increments, whose distributions collapse well for a wide range of scales.
format Preprint
id arxiv_https___arxiv_org_abs_2410_03237
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Extending Kolmogorov Theory to Polymeric Turbulence
Chiarini, Alessandro
Singh, Rahul K.
Rosti, Marco E.
Fluid Dynamics
The addition of polymers fundamentally alters the dynamics of turbulent flows in a way that defies Kolmogorov predictions. However, we now present a formalism that reconciles our understanding of polymeric turbulence with the classical Kolmogorov phenomenology. This is achieved by relying on an appropriate form of the Kármán-Howarth-Monin-Hill relation, which motivates the definition of extended velocity increments and the associated structure functions, by accounting for the influence of the polymers on the flow. We show, both analytically and numerically, that the ${\rm p}$th-order extended structure functions exhibit a power-law behaviour in the elasto-inertial range of scales, with exponents deviating from the analytically predicted value of ${\rm p}/3$. These deviations are readily accounted for by considering local averages of the total dissipation, rather than global averages, in analogy with the refined similarity hypotheses of Kolmogorov for classical Newtonian turbulence. We also demonstrate the scale-invariance of multiplier statistics of extended velocity increments, whose distributions collapse well for a wide range of scales.
title Extending Kolmogorov Theory to Polymeric Turbulence
topic Fluid Dynamics
url https://arxiv.org/abs/2410.03237