Experimental and Numerical Investigation on the Effect of Finger Spread on Swimmer Performance

Abstract

This study presents an experimental and numerical investigation on the effect of finger spread on the flow field around the swimmer's hand. Three hand models having different finger positions were analysed. The models were created by taking resin moulds of the hand of elite-level swimmer László Cseh. The models were digitised by high-resolution 3D scanning. Wind tunnel experiments were performed to measure the drag and lift forces acting on the hand. The measured data were also used to evaluate the performance of the CFD models in ANSYS Fluent. It was found that the magnitude of the drag force varied only slightly (by 1.65%) regarding the investigated cases; however, the maximum achievable lift increased significantly in the fully closed finger position. The difference in the measured maximum lift forces was ~67% between the fully open and fully closed finger positions. The numerical models underestimated the drag force but showed trends similar to the experimental results. The study highlights that while the finger spread influences the hydrodynamic forces acting on the swimmer's hand, the determination of an optimal finger spread requires further investigations considering the complete stroke trajectory. The presented methodology provides a solid foundation for future studies aimed to optimise swimmer performance and training.