Development of a vortex generator to perturb fish locomotion

Area of Science:

• Biomechanics
• Fluid Dynamics
• Ichthyology

Background:

• Understanding fish fin mechanics is crucial for aquatic locomotion.
• Previous studies lacked methods to assess fin stiffness during natural swimming.
• Instrumentation for in-situ mechanical analysis of fish fins was needed.

Purpose of the Study:

• To develop and validate a vortex generator for perturbing swimming fish fins.
• To investigate the mechanical properties of fish fins during active swimming.
• To correlate fin stiffness with swimming speed.

Main Methods:

• Development of a vortex generator producing adjustable strength traveling vortex rings.
• Characterization of vortex ring parameters (diameter, velocity).
• Perturbation of fish fins across a range of swimming speeds (0-350 mm/s).

Main Results:

• Successfully generated vortices with diameters from 14-32 mm and speeds from 371-2155 mm/s.
• Observed adequate fin responses to vortex perturbations.
• Collected data on fish fin mechanical properties during swimming.

Conclusions:

• The developed vortex generator is effective for studying fish fin mechanics in vivo.
• The study provides foundational data for understanding fin stiffness modulation during swimming.
• This research opens new avenues for investigating the biomechanics of aquatic propulsion.