In order to optimize the shape of the floating buoy of a multi-degree-of-freedom wave energy converter to improve its energy conversion efficiency, a method for shape optimization based on a genetic algorithm (GA) is proposed.

A B-spline surface is used to define the shape of the floating buoy, and the GA is applied to take all control points of the surface as individual variables in the iterative population. AQWA and WEC-Sim software are then used to establish a time-domain numerical model for each shape generated by the iteration, and the value of the objective function is calculated. The evolution curves of the objective function and optimized shape are then obtained. The effects of different schemes of shape definition and objective functions on the optimization results are studied and analyzed respectively.

The optimization method can significantly improve the energy conversion efficiency of a multi-degree-of-freedoms (DOFs) wave energy converter, and the shape definition scheme and objective function have a great impact on the final optimization results.

The results can provide a feasible design method for the shape optimization of the floating buoy of a multi-DOFs wave energy converter.