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  • Letter
  • Open Access

Giant superhydrophobic slip of shear-thinning liquids

Ory Schnitzer and Prasun K. Ray

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Phys. Rev. Fluids 9, L112201 – Published 26 November, 2024

DOI: https://doi.org/10.1103/PhysRevFluids.9.L112201

Abstract

We theoretically illustrate how complex fluids flowing over superhydrophobic surfaces may exhibit giant flow enhancements in the double limit of small solid fractions (ε≪1) and strong shear thinning (β≪1, β being the ratio of the viscosity at infinite shear rate to that at zero shear rate). Considering a Carreau liquid within the canonical scenario of longitudinal shear-driven flow over a grooved superhydrophobic surface, we show that, as β is decreased, the scaling of the effective slip length at small solid fractions is enhanced from the logarithmic scaling ln(1/ε) for Newtonian fluids to the algebraic scaling 1/ε1−nn, attained for β=O(ε1−nn), n∈(0,1) being the exponent in the Carreau model. We illuminate this scaling enhancement and the geometric-rheological mechanism underlying it through asymptotic arguments and numerical simulations.

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References (22)

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  22. We do not directly solve the reduced problem for (ŵ,λ̂). As shown in the SM, that reduced problem entails a modified local behavior approaching the ridge-top edges.

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Phys. Rev. Fluids 9, L112201– Published 26 November, 2024
  • Received 14 September 2024
  • Accepted 6 November 2024
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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