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

By S. Srinivasan, Wonjae Choi, Kyoo-Chul Park, Shreerang S. Chhatre, R. Cohen, G. H. McKinley. 2013

148 citations recorded by the source corpus.

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 rϕs are found to be consistent with existing analytic predictions.

Subfields: Computational Mechanics, Mechanics of Materials, Surfaces, Coatings and Films

View Paper: https://www.semanticscholar.org/paper/7df595731a25e13d358238edc05da9f632481c33

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Computational Mechanics

In Mechanics of Materials

In Surfaces, Coatings and Films

Citations in the corpus

Superhydrophobic drag reduction in laminar flows: a critical review (2016, methodology): “Srinivasan et al. (2013) measured the slip lengths on dual-textured spray-coated SHPo mesh surfaces using parallel plate rheometry while monitoring the location of the liquid–air interface at a given pressure.”
Characterization of superhydrophobic surfaces for drag reduction in turbulent flow (2018, background): “Insufficient mechanical durability is one reason SHSs have previously not shown sustainable friction reduction in turbulent flow (Zhao et al. 2007; Aljallis et al. 2013; Srinivasan et al. 2013; Bidkar et al. 2014; Ling et al. 2016).”