The Study On Hydrodynamic Performance Of Saucer-Like Wave Energy Converter

Wave energy is becoming one of the research focuses in the field of ocean energy. Wave energy in China is abundant. To investigate the wave energy converter is extremely important to alleviate the energy crisis and environmental pressure. Saucer-like overtopping wave energy converter is a new offshore wave energy converter. It has the advantages of high conversion efficiency, excellent adaptability and good stability. In order to develop the Saucer-like overtopping wave energy converter practically, both physical model experiment and numerical simulation are employed to study the wave energy converting systemically.The geometric configuration and anchoring scheme of the device is proposed and the structure size is determined in this paper. The floating performance of the device is studied by analysing the force on it and establishing the motion equation of its main structure.In the experimental study, it is found that the overtopping discharge is related to the incident wave parameters. The effects of the freeboard and guide vanes on the wave energy capture capability of the device are studied. The relationship between the overtopping discharge and flow is also investigated. The performance of the device in the sea condition is simulated by the irregular wave tests.The 3D numerical wave tank is established based on Reynolds time-averaged control equation and VOF model. It is found that the overtopping phenomenon can be reasonably simulated by the 3D numerical wave tank. The numerical results of overtopping discharge show good agreement with the model test results. The 3D wave tank is also applied to solve some problems of model tests.In the 3D numerical study, the effect of the number of guide vanes on the device performance is evident within certain limits. Considering the effect of the duct diameter on the outflow through which the water goes back to the sea, the select of diameter must be based on consideration of overtopping and turbine's obstacle effect. The orifice can be applied to simulating the flow rate change in the duct induced by the turbine. Combining the results of model test and numerical simulation, the key shape parameters of the device are determined. The optimum incident wave parameters and the range of freeboard for the device are provided.