Abstract
For continuous operation in harsh sea conditions, such as those seen in the North and Norwegian seas during the winter season, a floater must demonstrate reduced amplitudes of motion. A concept of a motion-compensations mechanism has been proposed that can cancel, or at least diminish, the level of such motions. In this context, a three-column asymmetric semisubmersible floater with passive motion-control technology, dubbed “Sakayan”, is discussed. This new floater concept can be used for offshore wind power generation, as well as for well interventions. Passive control is performed through the usage of air chambers, which are placed inside each of its three columns. This is a continuation of previous research efforts to investigate the effectiveness of air chambers to compensate for heave motion. This work aims to further study the dynamics of this floater and verify its capability to ameliorate the heave and pitch/roll motions. Numerical simulations are carried out using commercial software in the frequency and time domains. Results show that the presence of air chambers reduces the amplitude of motion for most of the six degrees of freedom and wave/wind incidence angles, albeit complete elimination is not achieved. Further studies are necessary concerning the application of an active control system for the present floater concept.
