Front-back asymmetry controls the impact of viscoelasticity on helical swimming
arXiv:2012.01579 · doi:10.1103/PhysRevFluids.6.043102
Abstract
We conduct experiments with force-free magnetically-driven rigid helical swimmers in Newtonian and viscoelastic (Boger) fluids. By varying the sizes of the swimmer body and its helical tail, we show that the impact of viscoelasticity strongly depends on the swimmer geometry: it can lead to a significant increase of the swimming speed (up to a factor of five), a similar decrease (also up to a factor of five) or it can have approximately no impact. Analysis of our data along with theoretical modeling shows that the influence of viscoelasticity on helical propulsion is controlled by a snowman-like effect, previously reported for dumbbell swimmers, wherein the front-back asymmetry of the swimmer leads to a non-Newtonian elastic force that can either favor or hinder locomotion.
References in corpus (14)
- The hydrodynamics of swimming microorganisms
- Bacterial hydrodynamics
- Propulsion in a viscoelastic fluid
- Undulatory swimming in viscoelastic fluids
- Locomotion of helical bodies in viscoelastic fluids: enhanced swimming at large helical amplitudes
- Swimming speeds of filaments in nonlinearly viscoelastic fluids
- Theory of swimming filaments in viscoelastic media
- Fluid elasticity increases the locomotion of flexible swimmers
- Helical propulsion in shear-thinning fluids
- Undulatory swimming in fluids with polymer networks
- The effect of gait on swimming in viscoelastic fluids
- Viscoelastic propulsion of a rotating dumbbell
- Orientation dependent elastic stress concentration at tips of slender objects translating in viscoelastic fluids
- Micropropulsion and microrheology in complex fluids via symmetry breaking