Is the zero Reynolds number approximation valid for ciliary flows?

Title

Is the zero Reynolds number approximation valid for ciliary flows?

 Author

Wei, D. (TU Delft BN/Marie-Eve Aubin-Tam Lab)
Ghoddoosi Dehnavi, P. (TU Delft Fluid Mechanics) ORCID 0000-0001-7531-3675
Aubin-Tam, M.E. (TU Delft BN/Marie-Eve Aubin-Tam Lab) ORCID 0000-0001-9995-2623
Tam, D.S.W. (TU Delft Fluid Mechanics) ORCID 0000-0001-5300-0889

 Date

2019

 Abstract

Stokes equations are commonly used to model the hydrodynamic flow around cilia on the micron scale. The validity of the zero Reynolds number approximation is investigated experimentally with a flow velocimetry approach based on optical tweezers, which allows the measurement of periodic flows with high spatial and temporal resolution. We find that beating cilia generate a flow, which fundamentally differs from the stokeslet field predicted by Stokes equations. In particular, the flow velocity spatially decays at a faster rate and is gradually phase delayed at increasing distances from the cilia. This indicates that the quasisteady approximation and use of Stokes equations for unsteady ciliary flow are not always justified and the finite timescale for vorticity diffusion cannot be neglected. Our results have significant implications in studies of synchronization and collective dynamics of microswimmers.


 To reference this document use:

http://resolver.tudelft.nl/uuid:8c0213c0-84f9-489d-9b09-4a01e78dd4d7

 DOI

https://doi.org/10.1103/PhysRevLett.122.124502

 ISSN

0031-9007

 Source

Physical Review Letters, 122 (12)

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

© 2019 D. Wei, P. Ghoddoosi Dehnavi, M.E. Aubin-Tam, D.S.W. Tam
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