Optimal Shape of Hands on Competitive Swimming

Abstract

Competitive swimming requires thrust force much greater than recreational swimming. Four configurations of hand paddles are investigated to obtain an optimal form of a hand in freestyle swimming scientifically. These configurations are a cup-shaped hand with fingers spaced apart, a flat one with fingers spaced apart and those with fingers closed. Aerodynamic forces and flow-induced vibration acting on these hand replicas are experimented with a 3 component load cell. The angle of attack into a hand paddle is related to its thrust efficiency and thrust force. The angle of attack for maximal thrust force is affected by the hand forms, especially with the existence of spacing between the fingers in this study. With these facts, the optimal hand forms are different according to a method of swimming such as S-shaped-pull pattern swimming and drag swimming. Moreover, magnitude of fluid-induced vibration acting on a driving hand varies according to the spacing of fingers and the hand forms.