1A2-A14 Bio-inspired Propulsion Mechanism in Fluid Using Variable Stiffness Fin by Torsion of Rectangular Elastic Plates : Propulsion Characteristics in a Uniform Flow(Bio-Mimetics and Bio-Mechatronics (2))

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. A hardened steel band SK, which has a low temperature dependence and high durability, was used for the elastic plate of the variable stiffness fin. The stiffness of the fin was changed by the torsional angle of two rectangular elastic plates. We discussed the behavior of the fin and the propulsion characteristics in a uniform flow of water.