Rana, N and Chatterjee, R and Ro, S and Levine, D and Ramaswamy, S and Perlekar, P (2024) Defect turbulence in a dense suspension of polar, active swimmers. In: Physical Review E, 109 (2).
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Abstract
We study the effects of inertia in dense suspensions of polar swimmers. The hydrodynamic velocity field and the polar order parameter field describe the dynamics of the suspension. We show that a dimensionless parameter R (ratio of the swimmer self-advection speed to the active stress invasion speed Phys. Rev. X 11, 031063 (2021)2160-330810.1103/PhysRevX.11.031063) controls the stability of an ordered swimmer suspension. For R smaller than a threshold R1, perturbations grow at a rate proportional to their wave number q. Beyond R1 we show that the growth rate is O(q2) until a second threshold R=R2 is reached. The suspension is stable for R>R2. We perform direct numerical simulations to characterize the steady-state properties and observe defect turbulence for R<R2. An investigation of the spatial organization of defects unravels a hidden transition: for small R�0 defects are uniformly distributed and cluster as R�R1. Beyond R1, clustering saturates and defects are arranged in nearly stringlike structures. © 2024 authors. Published by the American Physical Society.
| Item Type: | Journal Article |
|---|---|
| Publication: | Physical Review E |
| Publisher: | American Physical Society |
| Additional Information: | The copyright for this article belongs to the author. |
| Keywords: | Defects; Suspensions (fluids), Active stress; Dense suspension; Dimensionless parameters; Hydrodynamic velocity; Order parameter; Polar order; R ratio; Self-advection; Velocity field; Wave numbers, Turbulence |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 04 Apr 2024 11:57 |
| Last Modified: | 04 Apr 2024 11:57 |
| URI: | https://eprints.iisc.ac.in/id/eprint/84712 |
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