Polymer rheology simulations at the meso- and macroscopic scale

¹  Instituut-Lorentz for Theoretical Physics, Universiteit Leiden - P.O. Box 9506, 2300 RA Leiden, The Netherlands, EU
²  UPMC Univ Paris 06, Univ Paris-Sud, CNRS, UMR 7608, Lab FAST - Campus Univ, F-91405, Orsay, France, EU
³  Department of Physics and Centre for Complexity Science, University of Warwick - Coventry CV4 7AL, UK, EU
⁴  School of Physics, JCMB, King's Buildings, University of Edinburgh - Mayfield Road, Edinburgh EH9 3JZ, Scotland, UK, EU

Corresponding author: sultan@fast.u-psud.fr

Received: 24 July 2009
Accepted: 8 June 2010

Abstract

We show that simulations of polymer rheology at a fluctuating mesoscopic scale and at the macroscopic scale where flow instabilities occur can be achieved at the same time with dissipative particle dynamics (DPD) technique. We model the viscoelasticity of polymer liquids by introducing a finite fraction of dumbbells in the standard DPD fluid. The stretching and tumbling statistics of these dumbbells is in agreement with what is known for isolated polymers in shear flows. At the same time, the model exhibits behaviour reminiscent of drag reduction in the turbulent state: as the polymer fraction increases, the onset of turbulence in plane Couette flow is pushed to higher Reynolds numbers. The method opens up the possibility to model non-trivial rheological conditions with ensuing coarse-grained polymer statistics.