Influence of insoluble surfactants on shear flow over a surface in Cassie state at large Péclet numbers
| Autor: | Tobias Baier, Steffen Hardt |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Mechanical Engineering Microfluidics Slip (materials science) Flow direction Condensed Matter Physics 01 natural sciences 010305 fluids & plasmas Condensed Matter::Soft Condensed Matter Physics::Fluid Dynamics Surface tension Pulmonary surfactant Mechanics of Materials 0103 physical sciences Perpendicular Shear stress Composite material 010306 general physics Shear flow |
| Zdroj: | Journal of Fluid Mechanics. 907 |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2020.814 |
| Popis: | Surfactants can immobilize fluid–liquid interfaces under shear stress. We investigate the impact of insoluble surfactants on shear flow along a superhydrophobic surface in Cassie state, with gas trapped in grooves oriented perpendicular to the flow direction. Assuming convection-dominated transport along the gas–liquid interface, analytical results for the surfactant distribution on a groove and the corresponding flow field in its vicinity are derived both for a single groove and for an array of evenly spaced grooves. The results are elaborated for the case where the surface tension depends linearly on the surfactant concentration, which is characteristic for dilute coverage of the gas–liquid interface. For an array of grooves, the relation between the applied shear stress and the effective slip length on the microstructured surface is investigated. |
| Databáze: | OpenAIRE |
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