This paper focused on the experimental investigation of the influencing parameters of the
flap-type wave energy converters. We designed, tested, and analyzed different specifications of the flaps in order to evaluate their efficiency and establish the design guidelines for the bottom hinged flap type wave energy converters. The flap’s energy conversion efficiency was evaluated based on the average flow amount delivered by the hydraulic pump in a fixed period of time. It was observed from the experimental results that, when the wave height was relatively lower, the incident force on the flap was weaker; the delivered flow amount would be increased by adding the density and moment of inertia of the flap while keep the mass centre above the buoyancy centre. On the other hand, when the wave height was relatively higher, the incident force on the flap was stronger; then the delivered flow amount would be increased by adding the restoring
moment due to the buoyancy of the flap. This can be achieved by lowering the mass centre below the buoyancy centre of the flap while keeping low flap density and moment of inertia.
