Preferential Sampling and Small-Scale Clustering of Gyrotactic Microswimmers in Turbulence

Phys Rev Lett. 2016 Mar 11;116(10):108104. doi: 10.1103/PhysRevLett.116.108104. Epub 2016 Mar 10.

Abstract

Recent studies show that spherical motile microorganisms in turbulence subject to gravitational torques gather in down-welling regions of the turbulent flow. By analyzing a statistical model we analytically compute how shape affects the dynamics, preferential sampling, and small-scale spatial clustering. We find that oblong organisms may spend more time in up-welling regions of the flow, and that all organisms are biased to regions of positive fluid-velocity gradients in the upward direction. We analyze small-scale spatial clustering and find that oblong particles may either cluster more or less than spherical ones, depending on the strength of the gravitational torques.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cluster Analysis
  • Fractals
  • Gravitation
  • Gravity Sensing*
  • Hydrodynamics
  • Models, Statistical
  • Models, Theoretical*
  • Movement*
  • Swimming*