Chaotic mixing in effective compressible flows

R. Volk, C. Mauger, M. Bourgoin, C. Cottin-Bizonne, C. Ybert, and F. Raynal
Phys. Rev. E 90, 013027 – Published 30 July 2014

Abstract

We study numerically joint mixing of salt and colloids by chaotic advection and how salt inhomogeneities accelerate or delay colloid mixing by inducing a velocity drift Vdp between colloids and fluid particles as proposed in recent experiments [J. Deseigne et al., Soft Matter 10, 4795 (2014)]. We demonstrate that because the drift velocity is no longer divergence free, small variations to the total velocity field drastically affect the evolution of colloid variance σ2=C2C2. A consequence is that mixing strongly depends on the mutual coherence between colloid and salt concentration fields, the short time evolution of scalar variance being governed by a new variance production term P=C2·Vdp/2 when scalar gradients are not developed yet so that dissipation is weak. Depending on initial conditions, mixing is then delayed or enhanced, and it is possible to find examples for which the two regimes (fast mixing followed by slow mixing) are observed consecutively when the variance source term reverses its sign. This is indeed the case for localized patches modeled as Gaussian concentration profiles.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 28 March 2014

DOI:https://doi.org/10.1103/PhysRevE.90.013027

©2014 American Physical Society

Authors & Affiliations

R. Volk1,*, C. Mauger2, M. Bourgoin3, C. Cottin-Bizonne4, C. Ybert4, and F. Raynal2

  • 1Laboratoire de Physique de l'ENS de Lyon, CNRS UMR5672 and Université de Lyon, Lyon, France
  • 2LMFA, CNRS UMR5509, École Centrale Lyon, INSA de Lyon and Université de Lyon, Lyon, France
  • 3LEGI, CNRS UMR5519, Université Joseph Fourier, Université de Grenoble, Grenoble INP, France
  • 4Institut Lumière Matière, CNRS UMR5306, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France

  • *romain.volk@ens-lyon.fr

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 90, Iss. 1 — July 2014

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review E

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×