Geometry-induced rectification of looped oscillatory flows.

In this study, we leverage geometry-induced asymmetries to rectify oscillatory flows and induce net directional transport of fluid in a looped network. We demonstrate this valveless rectification phenomenon in an experimental apparatus that consists of an acrylic flow chamber with a deformable wall connected to a syringe pump via a T-junction. Here, oscillatory flows were forced by the syringe pump.

Simple analytic model for peristaltic flow and mixing.

Peristaltic flows occur when fluid in a channel is driven by periodic, traveling wall deformations, as in industrial peristaltic pumps, urethras, stomachs, and cochleae. Peristaltic flows often vary periodically at every point in space but nonetheless cause net transport and mixing of solutes because of Lagrangian (Stokes) drift. Direct numerical simulation can predict peristaltic flows but is computationally expensive, particularly for determining functional relationships between drive parameters and transport or mixing.