A unique design of a hybrid wave energy converter

A novel hybrid concept, which integrates the Raft Wave Energy Converter (RWEC) and Flap Wave Energy Converter (FWEC) designs, is introduced and evaluated as the Module Raft Wave Energy Converter (MRWEC) via a series of experimental and numerical tests. The MRWEC is composed of a modular flap and four rafts that are attached to the floating platform via hinges. The present WEC demonstrates a distinctive configuration, as it has the capability to effectively harness and convert wave energy, encompassing both its potential and kinetic forms, through the utilization of the flap and raft's pitch motion. The experimental investigation examines the motion characteristics, performance, and optimal conditions of the 1:32-scale MRWEC using a water channel under both situations of regular and irregular wave wave characteristics. The hydrodynamic characteristics of the small-scale MRWEC was systematically assessed by comparing the experimental data with corresponding findings obtained from ANSYS-AQWA. The results reveal that the capture factor of the MRWEC is strongly influenced by five key parameters: significant wave height, wave height, average wave energy period, wave period, and Power Take-Off (PTO) damping. The capture factors of the MRWEC, a combination of modular flap and rafts, exceed those of the FWEC without rafts by 27.7 % and 6.7 % under regular and irregular waves, respectively. It implies that rafts play multifunctional devices with significant roles being played in the hybrid concept of the WEC by floating the flap converter, harnessing and converting energy of the wave into mechanical energy, and thereby enhancing the overall performance of the typical FWEC. The MRWEC achieves a maximum capture factor of 29.2 % and 9 % when operating in regular and irregular waves, respectively. Overall, the experimental results align well with the corresponding data from ANSYS-AQWA across all operational conditions.