| Autor: |
Reinken, Henning, Klapp, Sabine H. L., Wilczek, Michael |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Phys. Rev. Fluids 7, 084501 (2022) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevFluids.7.084501 |
| Popis: |
Microswimmer suspensions self-organize into complex spatio-temporal flow patterns, including vortex lattices and mesoscale turbulence. Here we explore the consequences for the motion of passive tracers, based on a continuum model for the microswimmer velocity field. We observe two qualitatively different regimes distinguished via the dimensionless Kubo number $K$. At advection strengths right above the transition to turbulence, the flow field evolves very slowly ($K \gg 1$) and the spatial vortex structures lead to dominant trapping effects. In contrast, deep in the turbulent state, much faster dynamics ($K \ll 1$) consistent with the so-called sweeping hypothesis leads to transport properties completely determined by the temporal correlations. In between ($K \approx 1$), we observe a regime of optimal transport, signaled by a maximum of the diffusion coefficient. |
| Databáze: |
arXiv |
| Externí odkaz: |
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