Collective motion of microorganisms in complex fluids (INVITED)

Abstract eng:
Suspensions of microorganisms are characterized by large scale correlated flow structures, enhanced diffusion of passive tracers, and enhanced fluid mixing. Most previous studies on the collective motion of microorganisms have been limited to Newtonian fluids. The nonNewtonian fluid properties, such as viscoelasticity and shear-dependent viscosity in biological flows, such as saliva, mucus and biofilm, significantly affect the swimming dynamics of a single swimmer. However, the role of fluid rheology on the collective motion of microorganisms is poorly understood. In this work, we use direct numerical simulations to investigate the effects of fluid properties on the collective motion of rod-like microswimmers in a low Reynolds number regime. For both pushers and pullers, we find that the viscoelasticity does not qualitatively alter the collective motion of microorganisms. The average speed and spatial correlations in a suspension of pushers decrease with Deborah number, but they are less affected for pullers.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket