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Understanding the role of hydrodynamic interactions in fish swimming may help explain why and how fish swim in schools. In this work, we designed controlled experiments to study fish swimming in a disturbed flow. Specifically, we recorded the tail beat frequency of a fish swimming in the presence of an actively-controlled airfoil pitching at varying frequencies. We propose an information-theoretic approach to quantify the influence of the motion of the pitching airfoil on the animal swimming. The theoretical framework developed in this work may inform future investigations on the mechanisms underlying schooling in groups.
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Experimental study of the hydrodynamic interaction between a fish and an actively pitching airfoil
The phenomenon of fish schooling - coordinated swimming of fish in polarized groups of specific spatial formations- is commonly observed in several species of fish. Fish schooling may even provide hydrodynamic advantages reducing the overall swimming cost of the group. To date, the role of hydrodynamics in coordinated swimming is not completely understood as it is difficult to separately study the role of hydrodynamic interaction from other forms of interaction between the fish. Here, we propose a statistical methodology based on information theoretic tools and flow velocity measurements, that can potentially tease out the hydrodynamic interaction pathways from visual and tactile ones. To avoid experimental confounds from bidirectional interactions and objectively understand cause-and-effect relationships, we design a robotic platform that mimics the behavior of two fish swimming in-line in a controlled setup inside a water channel. We examine the response of a flag to the fish-like unsteady wake generated by an actively pitching airfoil located upstream. We systematically quantify the passive hydrodynamic effect by studying the flapping motion of the flag located downstream of the airfoil in response to both periodic pitching and less predictable, random startling motion of the upstream airfoil. The study integrates experimental biomimetics with information theory to establish a deeper understanding of hydrodynamics in fish schooling.
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- Award ID(s):
- 1901697
- PAR ID:
- 10552847
- Editor(s):
- Lakhtakia, Akhlesh; Martín-Palma, Raúl J; Knez, Mato
- Publisher / Repository:
- SPIE
- Date Published:
- ISSN:
- 10.1117/12.2658455
- ISBN:
- 9781510660694
- Page Range / eLocation ID:
- 11
- Format(s):
- Medium: X
- Location:
- Long Beach, United States
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1117/12.2658455
