English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this article, we study numerically the dispersion of colloids in atwo-dimensional cellular flow in the presence of an imposed mean salt gradient.Owing to the additional scalar, the colloids do not follow exactly the Eulerianflow field, but have a (small) extra-velocity proportional to the saltgradient, $\mathbf{v}_\mathrm{dp}=\alpha\nabla S$, where $\alpha$ is thephoretic constant and $S$ the salt concentration. We study the demixing of anhomogenous distribution of colloids and how their long-term mean velocity$\mathbf{V_m}$ and effective diffusivity $D_\mathrm{eff}$ are influenced by thephoretic drift. We observe two regimes of colloids dynamics depending on ablockage criterion $R=\alpha G L/\sqrt{4 D_cD_s}$, where $G$ is the mean saltgradient amplitude, $L$ the length scale of the flow and $D_c$ and $D_s$ themolecular diffusivities of colloids and salt. When $R<1$, the mean velocity isstrongly enhanced with $V_m \propto \alpha G \sqrt{Pe_s}$, $Pe_s$ being thesalt P\'eclet number. When $R> 1$, the compressibility effect due to thephoretic drift is so strong that a depletion of colloids occurs along theseparatrices inhibiting cell-to-cell transport.

Phoresis in cellular flows: from enhanced dispersion to blockage