Experimental Study on Hydrodynamic Behaviors of Hybrid Floating Body With Cylinders

Abstract

In this study, in order to evaluate hydrodynamic behaviors of the hybrid floating body with cylinders, experimental studies were carried out. At first, two small-scale models of pontoon and hybrid with scale factor 1:75 were fabricated and tested under the wave loadings. Based on the measured data, hydrodynamic motions of the pitch, surge, drift force, and free decay motions were evaluated and compared with each other. As the result of small-scale test, it was found that the pitch motion is more sensitive to the wave period than the surge and drift motions. Whereas the pitch motion increased by increasing of the wave period, the surge and drift motion presented a small variance according to the increasing of the wave period for the both models of pontoon and hybrid. Also, it was found that the hybrid floating body significantly influenced on the hydrodynamic motions under the wave loadings. The pitch motion reduced significantly for the all wave period cases. The surge and drift motion reduced over the wave period of 0.982sec. Damping properties of hybrid model indicated more favorable in terms of logarithmic decrement and damping ratio because of the shape effects. Therefore, it was expected that the hybrid model of this study contribute to improve serviceability and safety of floating body as decreasing hydrodynamic motions.