The cost of swimming in generalized Newtonian fluids: Experiments with C. elegans
arXiv:1610.05811 · doi:10.1017/jfm.2016.420
Abstract
Numerous natural processes are contingent on microorganisms' ability to swim through fluids with non-Newtonian rheology. Here, we use the model organism Caenorhabditis elegans and tracking methods to experimentally investigate the dynamics of undulatory swimming in shear-thinning fluids. Theory and simulation have proposed that the cost of swimming, or mechanical power, should be lower in a shear-thinning fluid compared to a Newtonian fluid of the same zero-shear viscosity. We aim to provide an experimental investigation into the cost of swimming in a shear-thinning fluid from (i) an estimate of the mechanical power of the swimmer and (ii) the viscous dissipation rate of the flow field, which should yield equivalent results for a self-propelled low Reynolds number swimmer. We find the cost of swimming in shear-thinning fluids is less than or equal to the cost of swimming in Newtonian fluids of the same zero-shear viscosity; furthermore, the cost of swimming in shear-thinning fluids scales with a fluid's effective viscosity and can be predicted using fluid rheology and simple swimming kinematics. Our results agree reasonably well with previous theoretical predictions and provide a framework for understanding the cost of swimming in generalized Newtonian fluids.
References in corpus (4)
Cited by in corpus (6)
- The physics of active polymers and filaments
- Swimming efficiency in a shear-thinning fluid
- The mechanism of propulsion of a model microswimmer in a viscoelastic fluid next to a solid boundary
- Characteristic features of self-avoiding active Brownian polymers under linear shear flow
- A finite element method for simulating soft active non-shearable rods immersed in generalized Newtonian fluids
- Two-dimensional active polar semiflexible polymer under shear flow