Fluid mixing by curved trajectories of microswimmers

Abstract

We consider the tracer diffusion $D_{rr}$ that arises from the run-and-tumble motion of low Reynolds number swimmers, such as bacteria. Assuming a dilute suspension, where the bacteria move in uncorrelated runs of length $\lambda$, we obtain an exact expression for $D_{rr}$ for dipolar swimmers in three dimensions, hence explaining the surprising result that this is independent of $\lambda$. We compare $D_{rr}$ to the contribution to tracer diffusion from entrainment.

5 pages, 2 figures

References in corpus (5)

• Fluid dynamics and noise in bacterial cell-cell and cell-surface scattering
• Direct measurement of the flow field around swimming microorganisms
• Diffusion and spatial correlations in suspensions of swimming particles
• Fluctuations and Rheology in Active Bacterial Suspensions
• Influence of swimming strategy on microorganism separation by asymmetric obstacles

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