Preferential Sampling of Elastic Chains in Turbulent Flows

TL;DR

This paper investigates how elastic chains of tracers in turbulent flows preferentially sample vortical regions over strain regions, revealing the influence of elasticity and deformability on flow trapping behavior.

Contribution

It demonstrates that elastic chains exhibit distinct preferential sampling behavior in turbulence, differing from non-interacting tracers, and quantifies this effect based on elasticity and chain deformability.

Findings

Elastic chains are trapped in vortical regions, unlike non-interacting tracers.

The degree of preferential sampling depends on the chain's elasticity.

Modifying chain deformability affects flow trapping behavior.

Abstract

A string of tracers, interacting elastically, in a turbulent flow is shown to have a dramatically different behaviour when compared to the non-interacting case. In particular, such an elastic chain shows strong preferential sampling of the turbulent flow unlike the usual tracer limit: an elastic chain is trapped in the vortical regions and not the straining ones. The degree of preferential sampling and its dependence on the elasticity of the chain is quantified via the Okubo-Weiss parameter. The effect of modifying the deformability of the chain, via the number of links that form it, is also examined.