Jump to main content
Jump to site search

Issue 24, 2013
Previous Article Next Article

Drag reduction for viscous laminar flow on spray-coated non-wetting surfaces

Author affiliations

Abstract

We estimate the effective Navier-slip length for flow over a spray-fabricated liquid-repellent surface which supports a composite solid–air–liquid interface or ‘Cassie–Baxter’ state. The morphology of the coated substrate consists of randomly distributed corpuscular microstructures which encapsulate a film of trapped air (or ‘plastron’) upon contact with liquid. The reduction in viscous skin friction due to the plastron is evaluated using torque measurements in a parallel plate rheometer resulting in a measured slip length of bslip ≈ 39 μm, comparable to the mean periodicity of the microstructure evaluated from confocal fluorescence microscopy. The introduction of a large primary length-scale using dual-textured spray-coated meshes increases the magnitude of the effective slip length to values in the range 94 μm ≤ bslip ≤ 213 μm depending on the geometric features of the mesh. The wetted solid fractions on each mesh are calculated from free surface simulations on model sinusoidal mesh geometries. The trend in measured values of bslip with the mesh periodicity L and the computed wetted solid-fraction s are found to be consistent with existing analytic predictions.

Graphical abstract: Drag reduction for viscous laminar flow on spray-coated non-wetting surfaces

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Feb 2013, accepted on 28 Mar 2013 and first published on 25 Apr 2013


Article type: Paper
DOI: 10.1039/C3SM50445J
Citation: Soft Matter, 2013,9, 5691-5702
  • Open access: Creative Commons BY license
  •   Request permissions

    Drag reduction for viscous laminar flow on spray-coated non-wetting surfaces

    S. Srinivasan, W. Choi, K. Park, S. S. Chhatre, R. E. Cohen and G. H. McKinley, Soft Matter, 2013, 9, 5691
    DOI: 10.1039/C3SM50445J

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements