Dipole- and vortex sheet-based models of fish swimming

Area of Science:

• Fluid dynamics
• Biophysics
• Computational modeling

Background:

• Understanding fish swimming hydrodynamics is key to fish orientation and schooling.
• Potential flow models, especially dipole-based vortex models, are used for fish-environment interactions but require validation.

Purpose of the Study:

• To validate the accuracy of dipole-based models for fish swimming hydrodynamics.
• To develop an improved model for predicting fluid flow around swimming fish.

Main Methods:

• Computational fluid dynamics (CFD) simulations of fish swimming in channel flow.
• Reconstruction of carangiform swimming patterns from experimental data.
• Development and testing of a novel vortex sheet model.

Main Results:

• Dipole-based models capture general flow features but fail to predict elongated streamlines.
• The proposed vortex sheet model accurately predicts fluid flow around swimming fish.
• The vortex sheet model demonstrates improved accuracy across various flow speeds and channel widths.

Conclusions:

• The proposed vortex sheet model offers enhanced accuracy for fish hydrodynamics research.
• This model provides a robust basis for studying fish swimming and schooling behaviors.
• The improved model balances accuracy with a manageable increase in computational cost.