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RESEARCH PRODUCT
Flows and mixing in channels with misaligned superhydrophobic walls.
Jiajia ZhouOlga I. VinogradovaOlga I. VinogradovaOlga I. VinogradovaEvgeny S. AsmolovFriederike SchmidTatiana V. Nizkayasubject
Chemical Physics (physics.chem-ph)Materials scienceDissipative particle dynamicsFluid Dynamics (physics.flu-dyn)Reynolds numberFOS: Physical sciencesPhysics - Fluid DynamicsMechanicsCondensed Matter - Soft Condensed MatterFluid transportVortexPhysics::Fluid DynamicsTransverse planesymbols.namesakeClassical mechanicsShear (geology)DragPhysics - Chemical PhysicssymbolsSoft Condensed Matter (cond-mat.soft)Pressure gradientdescription
Aligned superhydrophobic surfaces with the same texture orientation reduce drag in the channel and generate secondary flows transverse to the direction of the applied pressure gradient. Here we show that a transverse shear can be easily generated by using superhydrophobic channels with misaligned textured surfaces. We propose a general theoretical approach to quantify this transverse flow by introducing the concept of an effective shear tensor. To illustrate its use, we present approximate theoretical solutions and Dissipative Particle Dynamics simulations for striped superhydrophobic channels. Our results demonstrate that the transverse shear leads to complex flow patterns, which provide a new mechanism of a passive vertical mixing at the scale of a texture period. Depending on the value of Reynolds number two different scenarios occur. At relatively low Reynolds number the flow represents a transverse shear superimposed with two co-rotating vortices. For larger Reynolds number these vortices become isolated, by suppressing fluid transport in the transverse direction.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-09-23 | Physical review. E, Statistical, nonlinear, and soft matter physics |