Overtopping Wave Energy Convertor (OWEC) is an offshore wave energy convertor for collecting the overtopping waves and converting the water pressure head into electric power through the hydro turbines installed in the vertical duct which is fixed in the sea bed. The numerical wave tank based on the commercial computational fluid dynamics code Fluent is established for the corresponding analysis. The Reynolds Averaged Navier-Stokes and two-phase VOF model are utilized to generate the 2D numerical linear propagating waves, which has been validated by the overtopping experiment results. Several incident wave conditions and shape parameters of the overtopping device are calculated. The straight line type and parabolic type of the sloping arm are compared in the optimal designing investigation of the overtopping characteristics and discharge for OWEC device. The numerical results demonstrate that the parabolic sloping arm is available for wave running up and the overtopping discharge increasing.
Among various ocean renewable resources, wave energy is most abundantly available and applicable in most coastal and offshore areas. Due to the advantages of simple converting techniques and producing cost over other types of ocean energy, the wave energy conversion system is feasible to be established for the commercial power production. Plenty of wave energy absorption devices and plants have been invented, and several of them have been utilized in the electricity generation. Recently, the oscillating water column type has been widely employed in the application for the wave energy conversion. The disadvantage of this type is the low wave energy converting efficiency. Overtopping Wave Energy Convertor (OWEC) has the sloping walls and reservoirs to lift water waves to the levels above the average surrounding ocean. The released reservoir water is used to drive hydro turbines or other converting devices.