Author ORCID Identifier
Robert D. Guy: 0000-0002-0602-7015
Document Type
Article
Publication Date
2024
Publication Title
Interface
Abstract
Many microorganisms propel themselves through complex media by deforming their flagella. The beat is thought to emerge from interactions between forces of the surrounding fluid, the passive elastic response from deformations of the flagellum and active forces from internal molecular motors. The beat varies in response to changes in the fluid rheology, including elasticity, but there are limited data on how systematic changes in elasticity alter the beat. This work analyses a related problem with fixed-strength driving force: the emergence of beating of an elastic planar filament driven by a follower force at the tip of a viscoelastic fluid. This analysis examines how the onset of oscillations depends on the strength of the force and viscoelastic parameters. Compared to a Newtonian fluid, it takes more force to induce the instability in viscoelastic fluids, and the frequency of the oscillation is higher. The linear analysis predicts that the frequency increases with the fluid relaxation time. Using numerical simulations, the model predictions are compared with experimental data on frequency changes in the bi-flagellated alga Chlamydomonas reinhardtii. The model shows the same trends in response to changes in both fluid viscosity and Deborah number and thus provides a possible mechanistic understanding of the experimental observations.
Keywords
viscoelastic fluid, flagella, dynamic buckling instability, follower force
Volume
21
DOI
https://doi.org/10.1098/rsif.2024.0046
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Rights
© 2024 The Authors.
Recommended Citation
Link, Kathryn G.; Guy, Robert D.; Thomases, Becca; and Arratia, Paulo E., "Effect of Fluid Elasticity on the Emergence of Oscillations in an Active Elastic Filament" (2024). Mathematics Sciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/mth_facpubs/183
Comments
Archived as published.