Targeted mixing in an array of alternating vortices

TL;DR

This paper investigates how specific perturbations in an array of vortices can enhance local mixing while maintaining transport barriers, with implications for controlling fluid transport in complex flows.

Contribution

It introduces targeted perturbations that preserve transport barriers and optimize mixing in vortex arrays, expanding understanding of chaotic advection control.

Findings

Optimal mixing regions identified through numerical analysis

Transport barriers effectively prevent long-range transport

Robustness of mixing properties under boundary condition variations

Abstract

Transport and mixing properties of passive particles advected by an array of vortices are investigated. Starting from the integrable case, it is shown that a special class of perturbations allows one to preserve separatrices which act as effective transport barriers, while triggering chaotic advection. In this setting, mixing within the two dynamical barriers is enhanced while long range transport is prevented. A numerical analysis of mixing properties depending on parameter values is performed; regions for which optimal mixing is achieved are proposed. Robustness of the targeted mixing properties regarding errors in the applied perturbation are considered, as well as slip/no-slip boundary conditions for the flow.