Tag: Locomotion

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Confinement-driven state transition and bistability in schooling fish

B. Lafoux, P. Bernard, B. Thiria, R. Godoy-Diana
Physical Review E, 110(3), 034613 (2024).
doi: 10.1103/PhysRevE.110.034613
arXiv preprint: https://arxiv.org/abs/2401.01850

In this work we have quantified how fish swimming in groups change their behavior based on how crowded they are. We found that fish switch between two main swimming patterns: moving in the same direction or circling like a whirlpool. The amount of space available influences how long the fish stick to each pattern and how often they switch. This research not only helps us understand how fish and other animals behave in groups, but also provides valuable real-world data that can help tuning computer models of group behavior. The findings highlight the importance of considering space limitations when studying how animals move together, which could lead to better understanding of complex group behaviors in nature.

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Form and function of anguilliform swimming: a review

V. Stin, R. Godoy-Diana, X. Bonnet, & A. Herrel
Biological Reviews (2024)
doi: 10.1111/brv.13116

Anguilliform swimmers are long and narrow animals that propel themselves by undulating their bodies. Observations in nature and recent investigations suggest that anguilliform swimming is highly efficient. However, understanding the underlying reasons for the efficiency of this type of locomotion requires interdisciplinary studies spanning from biology to hydrodynamics. Regrettably, these different fields are rarely discussed together, which hinders our ability to understand the repeated evolution of this swimming mode in vertebrates. This review compiles the current knowledge of the anatomical features that drive anguilliform swimming, compares the resulting kinematics across a wide range of anguilliform swimmers, and describes the resulting hydrodynamic interactions using data from both in vivo experiments and computational studies.

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Volumetric velocimetry of the wake of a swimming snake

We describe a method for measuring the 3D vortical structures produced by an anguilliform swimmer using volumetric velocimetry. The wake of freely swimming dice snakes (Natrix tessellata) was quantified, revealing the creation of multiple vortices along the body of the snake due to its undulation. The 3D structure of the vortices generally consisted of paired vortex tubes, some of which were linked together to form a hairpin structure. The observations match predictions from computational fluid dynamic studies of other anguilliform swimmers. Quantitative measurements allowed us to study vortex circulation and size, and global kinetic energy of the flow, which varied with swimming speed, vortex topology and individual characteristics. Our findings provide a baseline for comparing wake structures of snakes with different morphologies and ecologies and investigating the energetic efficiency of anguilliform swimming.


V. Stin, R. Godoy-Diana, X. Bonnet, & A. Herrel. Measuring the 3D wake of swimming snakes (Natrix tessellata) using volumetric velocimetry.
Journal of Experimental Biology, 226, jeb245929 (2023)
doi: 10.1242/jeb.245929

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Special issue: Bioinspired fluid-structure interaction

https://iopscience.iop.org/journal/1748-3190/page/Bioinspired-Fluid-Structure-Interaction

Fluid-structure interaction (FSI) studies the interaction between fluid and solid objects. It helps understand how fluid motion affects solid objects and vice versa. FSI research is important in engineering applications such as aerodynamics, hydrodynamics, and structural analysis. It has been used to design efficient systems such as ships, aircraft, and buildings. FSI in biological systems has gained interest in recent years for understanding how organisms interact with their fluidic environment. Our special issue features papers on various biological and bio-inspired FSI problems.

S. Jung & R. Godoy-Diana
Bioinspiration & biomimetics 18, 030401 (2023)
Editorial article: 10.1088/1748-3190/acc778

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Intermittent vs. continuous swimming: An optimization tale

G. Li, D. Kolomenskiy, H. Liu, R. Godoy-Diana & B. Thiria
Physical Review Fluids 8, 013101 (2023)
doi: 10.1103/PhysRevFluids.8.013101
see also in Physics Magazine: Why Fish Swim Intermittently

Intermittent swimming, also termed “burst-and-coast swimming,” has been reported as a strategy for fish to enhance their energetical efficiency. Intermittent swimming involves additional control parameters, which complexifies its understanding by means of quantitative and parametrical analysis, in comparison with continuous swimming. In this study, we used a hybrid computational fluid dynamic (CFD) model to assess the swimming performance in intermittent swimming parametrically and quantitatively. A Navier-Stokes solver is applied to construct a database in the multidimensional space of the control parameters to connect the undulation kinematics to swimming performance. Based on the database, an indirect numerical approach named “gait assembly” is used to generate arbitrary burst-and-coast gaits to explore the parameter space. Our simulations directly measured the hydrodynamics and energetics under the unsteady added-mass effect during burst-and-coast swimming. The results suggest that the instantaneous power of burst is basically determined by undulatory kinematics. The results show that the energetical performance of burst-and-coast swimming can be better than that of continuous swimming, but also that an unoptimized burst-and-coast gait may become very energetically expensive. These results shed light on the mechanisms at play in intermittent swimming, enabling us to better understand fish behavior and to propose design guidelines for fishlike robots.

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Review paper: Fluid dynamic drag in animal swimming and flying

On the diverse roles of fluid dynamic drag in animal swimming and flying
R. Godoy-Diana & B. Thiria
Journal of the Royal Society Interface 15 20170715 (2018)
[doi:10.1098/rsif.2017.0715]

Questions of energy dissipation or friction appear immediately when addressing the problem of a body moving in a fluid. For the most simple problems, involving a constant steady propulsive force on the body, a straightforward relation can be established balancing this driving force with a skin friction or form drag, depending on the Reynolds number and body geometry. This elementary relation closes the full dynamical problem and sets, for instance, average cruising velocity or energy cost. Continue reading “Review paper: Fluid dynamic drag in animal swimming and flying”

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Flapping elastic plates as a model of fish-like swimmers

Modelling of an actuated elastic swimmer
M. Piñeirua, B. Thiria & R. Godoy-Diana
Journal of Fluid Mechanics 829 731-750 (2017)
[doi:10.1017/jfm.2017.570]PDF file

We studied the force production dynamics of undulating elastic plates as a model for fish-like inertial swimmers. Using a beam model coupled with Lighthill’s large-amplitude elongated-body theory, we explore different localised actuations at one extremity of the plate (heaving, pitching and a combination of both) in order to quantify the reactive and resistive contributions to the thrust. The latter has the Continue reading “Flapping elastic plates as a model of fish-like swimmers”

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Synchronisation and pattern formation in fish swimming

Tetrafish2

Simple phalanx pattern leads to energy saving in cohesive fish schooling
I. Ashraf, H. Bradshaw, T. T. Ha, J. Halloy, R. Godoy-Diana, B. Thiria
PNAS 114 (36) 9599-9604 (2017)
[doi:10.1073/pnas.1706503114]PDF file

Synchronisation and collective swimming patterns in Hemigrammus bleheri
I. Ashraf, R. Godoy-Diana, J. Halloy, B. Collignon, B. Thiria
Journal of the Royal Society Interface 13 20160734 (2016)
[doi:10.1098/rsif.2016.0734] PDF file

The question of how individuals in a population organize when living in groups arises for systems as different as a swarm of microorganisms or a flock of seagulls. The different patterns for moving collectively involve a wide spectrum of reasons, such as evading predators or optimizing food prospection. Also, the schooling pattern has often been associated with an advantage in terms of energy consumption. We use a popular aquarium fish, the red nose tetra fish, Hemigrammus bleheri, which is known to swim in highly cohesive groups, to ana- lyze the schooling dynamics. In our experiments, fish swim in a shallow-water tunnel with controlled velocity, Continue reading “Synchronisation and pattern formation in fish swimming”

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Hydrodynamic constraints and evolution of aquatic snakes

snakesDoes aquatic foraging impact head shape evolution in snakes ?
M. Segall, R. Cornette, A-C. Fabre, R. Godoy-Diana & A. Herrel
Proceedings of the Royal Society B 283 20161645 (2016).
[doi:10.1098/rspb.2016.1645] PDF file

Evolutionary trajectories are often biased by developmental and historical factors. However, environmental factors can also impose constraints on the evolutionary trajectories of organisms leading to convergence of morphology in similar ecological contexts. The physical properties of water impose strong constraints on aquatic feeding animals by generating pressure waves that can alert prey and potentially push them away from the mouth. These hydrodynamic constraints have resulted in the independent evolution of suction feeding in most groups of secondarily aquatic tetrapods. Despite the fact that snakes cannot use suction, they have invaded the aquatic milieu many times independently. Here, we test whether the aquatic environment has constrained head Continue reading “Hydrodynamic constraints and evolution of aquatic snakes”