1A1-S07 Propulsion Mechanism in Fluid Using Fin Modeled on Caudal Fin of Fish : Application of Variable Stiffness Fin by Torsion of Elastic Rectangular Plates(Bio-Mimetics and Bio-Mechatronics(1))

Abstract

Recently, the use of a bio-inspired oscillating elastic fin has been proposed as an alternative propulsion mechanism in water. It is thought that the new mechanism will improve efficiency and safety, relative to the screw propeller. The optimum elasticity of the fin is not constant and changes based on swimming speed and task. However, it is very difficult to exchange fins of different stiffness while moving. We have developed a propulsion mechanism using a variable stiffness fin with torsional rectangular elastic plates. The stiffness of the fin was changed by the torsional angle of two rectangular elastic plates. We discussed the behavior of the fin, thrust force characteristics, and the flow field surrounding the fin in a still water and an uniform flow of water.