An Experimental Study for the Non-linear Motion Characteristics of an Asymmetric Rotor by Pontoons

Abstract

− In this study, regular wave tests were performed for pitch motion characteristics of a Salter’s duck type rotor model. In the model test, pontoons behind the rotor model, which is for the buoyancy of a truss-platform, were applied, and the different motion characteristics of the rotor model were investigated in accordance with existence and nonexistence of the pontoons. The experiments were performed in three different wave heights, and the experimental results were directly compared with frequency domain analysis results. From the model test, it could be found that the pontoons move the resonance period of the rotor, and the pitch motions of the rotor in the case of the relatively high wave height were largely varied in low wave periods compared to the resonance period of the rotor. Also, independently of the pontoons, the resonance periods of the rotor in three wave heights were moved to low wave period direction independently of the pontoons as the wave height rose. And the normalized pitch motions of the rotor by three wave heights decreased as the wave height rose.