Effective longitudinal slip over grooves encapsulated by a nearly inviscid lubricant

TL;DR

This paper derives the effective slip length for a grooved surface fully wetted by a nearly inviscid lubricant under shear flow, highlighting the dominant role of the lubricant in slip behavior unlike superhydrophobic surfaces.

Contribution

It provides a theoretical calculation of slip length for encapsulated grooved surfaces with nearly inviscid lubricants, a novel focus contrasting superhydrophobic surface analysis.

Findings

Slip length is significantly affected by the lubricant's near-inviscid nature.

Lubricant flow dominates the slip behavior in the encapsulated surface.

Contrast established with superhydrophobic surfaces where lubricant effects are minimal.

Abstract

We calculate the effective slip length for a rectangularly grooved periodic surface encapsulated (i.e., fully wetted) by a lubricant fluid and subjected to exterior shear flow parallel to the grooves. Our focus is the limit of a nearly-inviscid lubricant, where the ratio $\mu$ of the lubricant viscosity to that of the exterior fluid is small. This limit is singular for an encapsulated surface, indicating a dominant lubricant-flow effect - a stark contrast to superhydrophobic surfaces where the role of the lubricant is typically negligible.