Abstract
Cytoplasmic streaming circulates the contents of large eukaryotic cells, often with complex flow geometries. A largely unanswered question is the significance of these flows for molecular transport and mixing. Motivated by “rotational streaming” in Characean algae, we solve the advection-diffusion dynamics of flow in a cylinder with bidirectional helical forcing at the wall. A circulatory flow transverse to the cylinder’s long axis, akin to Dean vortices at finite Reynolds numbers, arises from the chiral geometry. Strongly enhanced lateral transport and longitudinal homogenization occur if the transverse Péclet number is sufficiently large, with scaling laws arising from boundary layers.
- Received 20 June 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.178102
©2008 American Physical Society
Viewpoint
The inner life of mesoorganisms
Published 20 October 2008
Some of the most ingenious ideas for designing microfluidic systems come from observing plants and animals. A study that quantifies the protein-driven helical flow of liquid in large plant cells, for instance, may well inspire micron-scale liquid mixers and sensors.
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