Simulation analysis of fin swimming using bi-fin

Abstract

Since competitive fin swimming using bi-fin is a relatively new sport, there are no research about swimming motion considering the characteristic of the fin. Therefore players determine their swimming motion based on their own sense and experience. In this research, a simulation model to assess the swimming motion was constructed by extending the swimming human simulation model SWUM. In this model, the fin was modeled as a series of five rigid plates. These plates were connected by virtual springs and dampers, by which forces according to relative distance and velocity acted.

Fin's elasticity was also represented by springs and dampers, by which torques according to relative angle and angular velocity acted. The fin parameters such as the shape, the rigidity, and the hydrodynamic coefficients, were determined by comparing the experimental results of the deformation and the force measurement with the results simulated in the same condition. Fin swimming was simulated in a standard crawl motion. It was found that the body was unstable.