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Oyster farming rafts are traditionally constructed from bamboo, which are susceptible to damage during typhoons. To overcome this, a promising solution of farming rafts made of highly flexible polyethylene is proposed. Since there are only a few studies to understand the bending deformation of elastic deformable bodies in waves, the elasticity of the highly flexible polyethylene needs to evaluated quantitatively. Therefore, a time-domain analysis model for evaluating the motion characteristics and deformation performance of the polyethylene rafts is implemented. In addition, 1:6.75 model scale tests were conducted in a water tank under regular waves. Aluminum plates with similar bending rigidity as the real scale model were employed and bending strains were measured at three locations on the aluminum plates. It is found that the results in terms of displacements and bending strains predicted by the numerical model agree well with the model scale test results. A sensitivity analysis is conducted on the numerical model to elucidate the performance of the highly flexible polyethylene rafts for oyster farming. • A coupled numerical model of rigid and elastic deformable bodies is implemented. • The motion of a raft in waves was measured through numerical analysis and tests. • Bending strain of the elastic deformable body was accurately evaluated by time-domain analysis. [ABSTRACT FROM AUTHOR]

Single-Point Mooring (SPM) is a cost-effective and promising solution that can be utilized to station a Floating Offshore Wind Turbine (FOWT). However, it poses new challenges such as wind tracking performance and slow-drift motion, which are unexplored. In this study, an attempt is made to understand the wind tracking performance of a new-type FOWT 'Optiflow' moored by SPM system. Real-Time Hybrid Model (ReaTHM) testing is conducted on a 1/60 scale model and motion about the moored point is observed. It is found from experiments that the model follows the wind in rated, cut-out and storm conditions. Forced yawing test is also carried out on a 1/200 scale model to obtain a database of slow-drift damping (SDD) force coefficient. A time-history simulation code is developed to incorporate the slow-drift motion response following the wind. Two cases of simulation, one with slow-drift damping and another without slow-drift damping are carried out. Comparing the experimental and simulation results, it is revealed that the simulation with slow-drift damping coefficient predicts the wind tracking phenomenon better than the simulation without slow-drift damping coefficient. It is concluded that slow-drift damping is an important factor while simulating the turning motion of 'Optiflow' about the moored point. • Wind tracking performance of a single-point moored floating offshore wind turbine. • 1/60 model scale experiment and numerical simulation. • Real-time hybrid model testing applied to model wind loads. • Forced yawing test conducted to create a database of slow-drift damping coefficient. • Important to evaluate slow-drift damping during wind vane. [ABSTRACT FROM AUTHOR]