Drag Reduction by Polymer Additives in Decaying Turbulence

TL;DR

This paper investigates how polymer additives can reduce drag in decaying turbulence through numerical simulations, revealing new spectral features, energy dynamics, and intermittency behaviors, and comparing these with established turbulence models.

Contribution

It introduces a novel definition of drag reduction in decaying turbulence and provides new insights into polymer energy spectra and temporal evolution of turbulence characteristics.

Findings

Identification of polymer potential-energy spectrum

Observation of new features in kinetic-energy decay

Characterization of intermittency in polymer-turbulence systems

Abstract

We present results from a systematic numerical study of decaying turbulence in a dilute polymer solution by using a shell-model version of the FENE-P equations. Our study leads to an appealing definition of drag reduction for the case of decaying turbulence. We exhibit several new results, such as the potential-energy spectrum of the polymer, hitherto unobserved features in the temporal evolution of the kinetic-energy spectrum, and characterize intermittency in such systems. We compare our results with the GOY shell model for fluid turbulence.