Flow past superhydrophobic surfaces with cosine variation in local slip length.

Phys Rev E Stat Nonlin Soft Matter Phys

A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia.

Published: February 2013

Anisotropic superhydrophobic surfaces have the potential to greatly reduce drag and enhance mixing phenomena in microfluidic devices. Recent work has focused mostly on cases of superhydrophobic stripes. Here, we analyze a relevant situation of cosine variation of the local slip length. We derive approximate formulas for maximal (longitudinal) and minimal (transverse) directional effective slip lengths that are in good agreement with the exact numerical solution and lattice-Boltzmann simulations. Compared to the case of superhydrophobic stripes, the cosine texture can provide a very large effective slip. However, the difference between eigenvalues of the slip-length tensor is smaller, indicating that the flow is less anisotropic.

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http://dx.doi.org/10.1103/PhysRevE.87.023005DOI Listing

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