Taylor dispersion of colloidal particles in narrow channels

Abstract

We use a mesoscopic particle-based simulation technique to study the classic convection-diffusion problem of Taylor dispersion for colloidal discs in confined flow. When the disc diameter becomes non-negligible compared to the diameter of the pipe, there are important corrections to the original Taylor picture. For example, the colloids can flow more rapidly than the underlying fluid, and their Taylor dispersion coefficient is decreased. For narrow pipes, there are also further hydrodynamic wall effects. The long-time tails in the velocity autocorrelation functions are altered by the Poiseuille flow.

Keywords:

• Taylor dispersion
• convection
• diffusion
• colloidal particles
• confinement effects

Acknowledgements

Jimaan Sané thanks Schlumberger Cambridge Research and Impact Faraday for an EPSRC CASE studentship which supported this work. Ard A. Louis thanks the Royal Society (London) for financial support. We thank H. Lekkerkerker for first suggesting to us that we study Taylor dispersion and R. Castillo for helpful discussions about Taylor dispersion experiments. We also thank Jean-Pierre Hansen for many years of inspirational conversations about coarse-graining techniques and much more.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The Royal Society (London) for financial support [grant number 516002.k5712].