Abstract
Recently, R&D of marine renewable energy becomes very popular all over the world. In this paper, a twin-type turbine is adopted as an ocean current power generator. The twin turbine system is theoretically torque free, since the left blade counters the right blade torque. Therefore, a floating body with a single point mooring concept can be used as a support of twin turbines. A computer code, which represents motions of the twin type current turbine with 6 degrees of freedom together with the non-linear mooring effect, is developed. The numerical code simulates fully coupled motions of the main body, two turbines and two mooring lines. The numerical results are validated with experiment in which a newly developed small size turbine ?generator model is used.The results show that the numerical results are in good agreement with the experimental results. Some numerical and experimental results show that the current turbine is stably moored even when the flow speed or direction is suddenly changed. The weather vane function of the mooring system is also demonstrated in the experiment.
