Effect of polymer-stress diffusion in the numerical simulation of elastic turbulence

TL;DR

This paper investigates how artificial polymer-stress diffusion affects the accuracy of numerical simulations of elastic turbulence, revealing significant impacts on flow properties and potential spurious phenomena.

Contribution

It provides a comparative analysis of simulations with and without artificial diffusion in elastic turbulence models, highlighting the effects on flow accuracy.

Findings

Artificial diffusion significantly alters large-scale flow properties.

Spurious phenomena can arise due to artificial diffusion.

Artificial diffusion may compromise the physical realism of simulations.

Abstract

Elastic turbulence is a chaotic regime that emerges in polymer solutions at low Reynolds numbers. A common way to ensure stability in numerical simulations of polymer solutions is to add artificially large polymer-stress diffusion. In order to assess the accuracy of this approach in the elastic-turbulence regime, we compare numerical simulations of the two-dimensional Oldroyd-B and FENE-P models sustained by a cellular force with and without artificial diffusion. We find that artificial diffusion can have a dramatic effect even on the large-scale properties of the flow and we show some of the spurious phenomena that may arise when artificial diffusion is used.