Geometry, elasticity, and activity in the transport of self-propelled filaments in turbulence
Abstract
We investigate the transport of elastic active filaments in two-dimensional turbulence, focusing on how propulsion geometry and elasticity determine vortex trapping and transport. Using a bead-spring model with activity applied at the filament head, we compare propulsion that follows the instantaneous filament conformation with propulsion imposed along a fixed external direction. We find that activity does not generically enhance transport: when propulsion remains coupled to the filament backbone, vortex trapping remains dominant and motion stays effectively diffusive, whereas fixed-direction propulsion enables persistent excursions across flow structures and leads to superdiffusive transport. In both cases, activity shifts filament conformations toward more extended states, effectively opposing elastic relaxation without eliminating preferential sampling of coherent vortical regions. At low Weissenberg number, this conformational change is amplified: activity cooperates with elasticity to enhance preferential sampling of vortical regions and strengthen vortex trapping. Transport therefore emerges from a competition between activity, elasticity, and flow-induced deformation, with elasticity determining how effectively activity-induced extensions can persist against turbulent trapping. These results establish propulsion geometry as the key control parameter for transport, with elasticity and activity acting cooperatively rather than independently to shape filament dynamics in turbulent flows.
Versions
Related
- Interactions Between Two Magnetized Plasma Pressure Filaments: Drift-Alfvén Modes and Transport
- Why MHD turbulence forms sheets: energy conversion and cascade geometry
- A Symplectic Theory of Turbulence Closure: Hidden Reservoir Dynamics, Endogenous Stochastic Transport, and Kraichnan Dual Cascades
- Drift wave turbulence and transport analysis of hot ion L-mode plasma with fishbone instability on the HL-3 tokamak
- Mobility Anisotropy Reshapes Self-Propelled Motion
BibTeX
@misc{kumar2026geometry,
title = {{Geometry, elasticity, and activity in the transport of self-propelled filaments in turbulence}},
author = {Kunal Kumar and Aliv Sahoo and Rahul Kumar Singh and Samriddhi Sankar Ray},
howpublished = {arXiv},
year = {2026},
month = may,
doi = {10.48550/arxiv.2605.24901},
eprint = {2605.24901},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.24901},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Geometry, elasticity, and activity in the transport of self-propelled filaments in turbulence
AU - Kunal Kumar
AU - Aliv Sahoo
AU - Rahul Kumar Singh
AU - Samriddhi Sankar Ray
PY - 2026
DA - 2026/05/24
PB - arXiv
DO - 10.48550/arxiv.2605.24901
UR - https://arxiv.org/abs/2605.24901
AB - We investigate the transport of elastic active filaments in two-dimensional turbulence, focusing on how propulsion geometry and elasticity determine vortex trapping and transport. Using a bead-spring model with activity applied at the filament head, we compare propulsion that follows the instantaneous filament conformation with propulsion imposed along a fixed external direction. We find that activity does not generically enhance transport: when propulsion remains coupled to the filament backbone, vortex trapping remains dominant and motion stays effectively diffusive, whereas fixed-direction propulsion enables persistent excursions across flow structures and leads to superdiffusive transport. In both cases, activity shifts filament conformations toward more extended states, effectively opposing elastic relaxation without eliminating preferential sampling of coherent vortical regions. At low Weissenberg number, this conformational change is amplified: activity cooperates with elasticity to enhance preferential sampling of vortical regions and strengthen vortex trapping. Transport therefore emerges from a competition between activity, elasticity, and flow-induced deformation, with elasticity determining how effectively activity-induced extensions can persist against turbulent trapping. These results establish propulsion geometry as the key control parameter for transport, with elasticity and activity acting cooperatively rather than independently to shape filament dynamics in turbulent flows.
ER -