Realising a biomimetic low-Vogel-exponent aquatic training device.

Area of Science:

• Fluid dynamics
• Biomechanics
• Biomedical engineering

Background:

• Aquatic resistance training uses devices like swimming parachutes to increase drag.
• Conventional parachutes have drag that scales quadratically with velocity, requiring constant speed for consistent resistance.
• This limits training adaptability and increases injury risk.

Purpose of the Study:

• To design and evaluate a bio-inspired swimming parachute with reduced drag-velocity scaling.
• To overcome limitations of conventional parachutes in aquatic resistance training.
• To explore the application of biological fluid-structure interaction in biomedicine.

Main Methods:

• Designed a flexible, squid-inspired swimming parachute.
• Experimentally evaluated the parachute's hydrodynamic performance under crawl swimming conditions.
• Measured drag force and velocity to determine the drag-velocity scaling (Vogel exponent).

Main Results:

• The bio-inspired parachute exhibited a low Vogel exponent (Ѵ) between -0.9 and -1.3.
• This indicates linear-to-sublinear drag force scaling with velocity, ensuring more consistent drag loading.
• Several morphological configurations demonstrated this improved resistance consistency.

Conclusions:

• Flexible, bio-inspired morphology can significantly weaken drag-velocity scaling in aquatic devices.
• This leads to more consistent resistance, potentially reducing injury risk in aquatic training and rehabilitation.
• The study highlights a novel link between fluid-structure interaction and biomedical applications.