The hydrodynamics of swimming microorganisms
The biophysical and mechanical principles of locomotion at the small scales relevant to cell swimming, tens of micrometers and below are reviewed, with emphasis on the simple physical picture and fundamental flow physics phenomena in this regime.
Effective slip in pressure-driven Stokes flow
Nano-bubbles have recently been observed experimentally on smooth hydrophobic surfaces; cracks on a surface can likewise be the site of bubbles when partially wetting fluids are used. Because these…
Swimming in circles: motion of bacteria near solid boundaries.
A hydrodynamic model is provided for near a solid boundary, Escherichia coli swims in clockwise circular motion and the radius of curvature of the trajectory is observed to increase with the length of the bacterium body.
Hydrodynamic attraction of swimming microorganisms by surfaces.
It is demonstrated theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their reorientation in the direction parallel to the surfaces, as well as their attraction by the closest wall, which compares favorably with measurements.
Propulsion in a viscoelastic fluid
- E. Lauga
- 21 March 2007
This work considers the simplest model of propulsion and transport in a complex fluid, a waving sheet of small amplitude free to move in a polymeric fluid with a single relaxation time, and shows that, compared to self-propulsion in a Newtonian fluid occurring at a velocity UN, the sheet swims or transports fluid with velocity U∕UN.
Hydrodynamics of self-propulsion near a boundary: predictions and accuracy of far-field approximations
Abstract The swimming trajectories of self-propelled organisms or synthetic devices in a viscous fluid can be altered by hydrodynamic interactions with nearby boundaries. We explore a multipole…
Geometric transition in friction for flow over a bubble mattress
Laminar flow over a bubble mattress is expected to experience a significant reduction in friction since the individual surfaces of the bubbles are shear-free. However, if the bubbles are sufficiently…
Spontaneous autophoretic motion of isotropic particles
It is demonstrated theoretically that anisotropy is not necessary for locomotion and that the nonlinear interplay between surface osmotic flows and solute advection can produce spontaneous and self-sustained motion of isotropic particles.
Waving transport and propulsion in a generalized Newtonian fluid
Microfluidics: The no-slip boundary condition
The no-slip boundary condition at a solid-liquid interface is at the center of our understanding of fluid mechanics. However, this condition is an assumption that cannot be derived from first…