The seaspoon wave energy converter: Performance characterization of different blade geometries

This paper describes the recent development of the innovative wave energy converter for off-shore applications named the Seaspoon. It is a wave energy converter (WEC) that catches the energy content of oceans waves exploiting the circular motion of the water particles perturbed at the free surface by the action of the wind. The paper describes the development and experimental validation of a CFD model, which will be used to optimise the geometry of Seaspoon blades, enabling its future scale-up. Such a model has been developed in the STAR-CCM+ environment. The model has been successfully compared against literature data for wave motion and forces against a static body. Then, the model has been compared against experimental measurements from the Seaspoon test campaign equipped with flat blades in a laboratory-scale wave tank, showing acceptable results in the prediction of the Seaspoon motion. Furthermore, experimental results on concave-type and convex-type blades are shown, demonstrating that the latter is the most promising shape: such blade type is currently object of CFD model validation and will be considered for the future development of the Seaspoon. The test campaign and the simulation studies contributed to identify the geometrical options to enhance the Seaspoon energy harvesting efficiency as well as adaptability to different sea-states.