Eur. Phys. J. E (2018) 41: 84
https://doi.org/10.1140/epje/i2018-11692-9

Regular Article

Enhancement of mixing by rodlike polymers

¹ Université Côte d’Azur, CNRS, LJAD, Nice, France
² Istituto dei Sistemi Complessi, CNR, via dei Taurini 19, 00185, Roma, Italy
³ INFN, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133, Roma, Italy
⁴ Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1, 3PU, UK

^* e-mail: stefano.musacchio@unice.fr

Received: 4 May 2018
Accepted: 25 June 2018
Published online: 11 July 2018

Abstract

We study the mixing of a passive scalar field dispersed in a solution of rodlike polymers in two dimensions, by means of numerical simulations of a rheological model for the polymer solution. The flow is driven by a parallel sinusoidal force (Kolmogorov flow). Although the Reynolds number is lower than the critical value for inertial instabilities, the rotational dynamics of the polymers generates a chaotic flow similar to the so-called elastic-turbulence regime observed in extensible polymer solutions. The temporal decay of the variance of the scalar field and its gradients shows that this chaotic flow strongly enhances mixing.