Strong polymer-turbulence interactions in viscoelastic turbulent channel flow

TL;DR

This study introduces a novel numerical method to simulate viscoelastic turbulent channel flow, revealing detailed polymer-turbulence interactions and mechanisms behind drag reduction, aligning closely with experimental observations.

Contribution

A new computational approach for viscoelastic turbulence that accurately captures polymer-turbulence interactions without artificial assumptions.

Findings

Enhanced understanding of polymer-turbulence energy transfer mechanisms

Numerical results closely match experimental observations

First implementation of this method in 3D channel flow

Abstract

This paper is focused on the fundamental mechanism(s) of viscoelastic turbulence that lead to polymer induced turbulent drag reduction phenomenon. A great challenge in this problem is the computation of viscoelastic turbulent flows, since the understanding of polymer physics is restricted to mechanical models. An effective state-of-the-art numerical method to solve the governing equation for polymers modelled as non-linear springs, without using any artificial assumptions as usual, was implemented here for the first time on a three-dimensional channel flow geometry. The capability of this algorithm to capture the strong polymer-turbulence dynamical interactions is depicted on the results, which are much closer qualitatively to experimental observations. This allowed a more detailed study of the polymer-turbulence interactions, which yields an enhanced picture on a mechanism resulting from the polymer-turbulence energy transfers.