Optimization of structural shape for wave energy converter based on B-spline surface and manufacturability

The gradual depletion of non-renewable resources, renewable energy sources such as wave energy have attracted significant attention and are being actively developed. However, wave energy converter with fixed geometries cannot adequately adapt to complex wave conditions, leaving room for further improvement in energy conversion efficiency. In this paper, the geometry of a buoy is parametrically described using bi-cubic B-spline surfaces, which are generated from a relatively small number of control points (including both fixed and variable points) to effectively reduce the search dimension. Specifically, several dimensionless parameters are defined to control the shape of the device, thereby achieving optimal conversion efficiency. We employ genetic algorithms to enhance the energy conversion efficiency of wave energy converter. To address the potential issue of excessive geometric curvature arising from variations in control points during buoy manufacturing, manufacturability is incorporated as a constraint in the optimization process. The method uses a limited parameter set to define the shape (represented by numerous points) of the submerged buoy structure, and during the surface transformation, after incorporating manufacturing constraints, the CWR exhibited a 78.00% improvement. This approach allows for an optimized WEC design with enhanced suitability. The results are evaluated under both regular and irregular wave conditions. This approach holds potential for extension to other, more complex underwater structures in the future.