Analysis on the split absorber integrated with taut-moored floating turbine

Abstract

A new wave energy converter is proposed in this paper, consisting of three split heave point absorbers, combined with a taut-moored floating turbine. It is adapted to the waves in the China Sea area, which are characterized by short periods and small amplitudes. Based on a series of physical model tests in regular, irregular, and extreme waves, the hydrodynamic performance of the integrated device is systematically investigated under different damping forces and incident wave directions. The experimental results reveal that the split point absorber presents new hydrodynamic characteristics and that the wave energy capture efficiency of the new device is greatly improved for the short-period waves in low sea states. Moreover, due to the out-of-phase heave motion, as well as the induced shallow water effect, the submerged platform makes a contribution to improving the energy capture efficiency of the split floater, particularly pronounced in the case of a high damping force in the power takeoff system. Under the condition of incident wave direction being coincident with the horizontal projection of mooring lines, the energies of pitch motion and mooring force of the integrated system are increased as a result of the high-frequency oscillation, which needs to be solved by further optimizing the taut mooring system.