Hydrodynamic and oscillatory motions of hybrid floating structure with cylinders

In this study, in order to investigate hydrodynamic and oscillatory motions of hybrid floating structure with cylinders, analytical and experimental studies were carried out on hybrid floating structures. In order to investigate hydrodynamic motions, hydrodynamic analyses were performed on the hybrid and pontoon models. Hydrodynamic analyses were carried out to the different incident wave of 0°, 45°, and 90° and hydrodynamic motions of heave, pitch, and surge were analyzed. Also, in order to investigate oscillatory motions, three small-scale models of hybrid, tapered, and pontoon were fabricated and tested under the still-water condition. Finally, oscillatory motions of oscillation period, stabilizing time to steady-state were analyzed. As the results of this study, it was found that the hydrodynamic motions of hybrid model, especially surge motion, were significantly reduced over the wave period 6 sec comparing with the pontoon model. Also, oscillatory motions of hybrid model were presented about 1.7 times longer oscillation period and 0.37 times shorter stabilizing time to steady-state than the pontoon model. Therefore, it was expected that the hybrid model of this study contribute to improve serviceability and safety of offshore floating structures as decreasing hydrodynamic and oscillatory motions.