Experimental Study on Modeled Caudal Fins Propelling by Elastic Deformation

Abstract

The present study proposes a new device for the experiment of self-propelling bodies in the water. As opposed to the studies in the past whose experiments were often carried out in a water channel with a given freestream velocity, the new device allows the model to swim under an actual self-propelling condition. The adopted model mimics the caudal fin of various shapes and made of elastic material, and the self-propelling speed is investigated primarily as a function of the forcing frequency. The influence of the amplitude of forced vibration and the materials of different elasticity is also investigated. The flow field around the model fin has been measured by PIV to characterize the flow pattern produced by the fin-motion.