# Axisymmetric squirmers in Stokes fluid with nonuniform viscosity

@article{Eastham2019AxisymmetricSI, title={Axisymmetric squirmers in Stokes fluid with nonuniform viscosity}, author={P. S. Eastham and Kourosh Shoele}, journal={arXiv: Fluid Dynamics}, year={2019} }

The ciliary locomotion and feeding of an axisymmetric micro-swimmer in a complex fluid whose viscosity depends on nutrient concentration are investigated numerically. The micro-swimmer is modeled as having spheroidal geometry, and ciliary beating is modeled by a slip velocity; i.e. a squirmer is adapted. Looking at the coupling between swimming and feeding of spheroidal squirmers, it is found that swimming speed and feeding are most affected by a non-uniform viscosity environment when the ratio…

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## References

SHOWING 1-10 OF 99 REFERENCES

Stirring by squirmers

- PhysicsJournal of Fluid Mechanics
- 2011

We analyse a simple ‘Stokesian squirmer’ model for the enhanced mixing due to swimming micro-organisms. The model is based on a calculation of Thiffeault & Childress (Phys. Lett. A, vol. 374, 2010,…

Generalized squirming motion of a sphere

- Physics
- 2014

A number of swimming microorganisms, such as ciliates (Opalina) and multicellular colonies of flagellates (Volvox), are approximately spherical in shape and swim using beating arrays of cilia or…

Locomotion of a microorganism in weakly viscoelastic liquids.

- EngineeringPhysical review. E, Statistical, nonlinear, and soft matter physics
- 2015

Results show that "neutral" squirmers are unaffected by viscoelasticity, whereas "pullers" and "pushers" are slowed down and hastened, respectively, and the power dissipated by the swimming microorganism and the "swimming efficiency" are analytically quantified.

Squirming motion in a Brinkman medium

- PhysicsJournal of Fluid Mechanics
- 2018

Micro-organisms encounter heterogeneous viscous environments consisting of networks of obstacles embedded in a viscous fluid medium. In this paper we analyse the characteristics of swimming in a…

Swimming efficiency in a shear-thinning fluid.

- Engineering, BiologyPhysical review. E
- 2017

This work considers the squirmer model as a general locomotion model to represent different types of swimmers and determines optimal shear rates at which the swimming efficiency can be substantially enhanced compared with the Newtonian case.

Squirming through shear-thinning fluids

- PhysicsJournal of Fluid Mechanics
- 2015

Many micro-organisms find themselves immersed in fluids displaying non-Newtonian rheological properties such as viscoelasticity and shear-thinning viscosity. The effects of viscoelasticity on…

Nutrient Uptake by a Self‐Propelled Steady Squirmer

- Physics
- 2003

Summary In this paper we study nutrient uptake by a very simple model of a swimming microorganism, a sphere moving its surface tangentially to itself with constant concentration on the surface. The…

Optimal feeding is optimal swimming for all P\'eclet numbers

- Environmental Science
- 2011

Cells swimming in viscous fluids create flow fields which influence the transport of relevant nutrients, and therefore their feeding rate. We propose a modeling approach to the problem of optimal…

The cost of swimming in generalized Newtonian fluids: experiments with C. elegans

- Biology, PhysicsJournal of Fluid Mechanics
- 2016

The model organism Caenorhabditis elegans is used and tracking methods are used to experimentally investigate the dynamics of undulatory swimming in shear-thinning fluids to provide a framework for understanding the cost of swimming in generalized Newtonian fluids.

Analysis of the swimming of microscopic organisms

- PhysicsProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences
- 1951

Large objects which propel themselves in air or water make use of inertia in the surrounding fluid. The propulsive organ pushes the fluid backwards, while the resistance of the body gives the fluid a…